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LIBRARY 

OF    THE 

UNIVERSITY  OF  CALIFORNIA. 


GENERAL 


METALLURGY  OF  CAST  IRON 


A   COMPLETE 

EXPOSITION   OF  THE   PROCESSES   INVOLVED  IN  ITS 
TREATMENT,     CHEMICALLY    AND    PHYSIC- 
ALLY, FROM  THE  BLAST  FURNACE 
THROUGH  THE  FOUNDRY 
TO    THE    TESTING 
MACHINE, 

A  Practical  Compilation  of  Original  Research. 


THOMAS  D.  WEST, 

PRACTICAL  MOULDER   AND    FOUNDRY    MANAGER;    MEMBER   OF   AMERICAN 
SOCIETY    OF     MECHANICAL    ENGINEERS,    AMERICAN    AND    PITTSBURG 

FOUNDRYMEN'S  ASSOCIATIONS,  AND  HONORARY  MEMBER  OF  FOUN- 
DRYMEN'S  ASSOCIATION  OF  PHILADELPHIA;  AUTHOR  OF  "AMERICAN 
FOUNDRY  PRACTICE,"  "  MOULDER'S  TEXT-BOOK;  "  "INSTRUCTION 
PAPERS  ON  FOUNDING,  FOR  THE  INTERNATIONAL  CORRESPOND- 
ENCE SCHOOLS,"  AND  ORIGINATOR  OF  THE  A.  F.  A.  STANDARD- 
IZED DRILLINGS  BUREAU. 


FULLY  ILLUSTRATED. 
SEVENTH  EDITION. 


CLEVELAND,  OHIO,  U.  S.  A. : 

THE  CLEVELAND  PRINTING  AND  PUBLISHING  CO.,  PUBLISHERS. 
I9O2. 


COPYRIGHT  1902. 
BY  THOMAS  D.  WEST, 


GENERAL 


VIHiMC*    U*rT. 


TABLE  OF  CONTENTS. 


PART  I. 

TREATS  OF  MANUFACTURE  AND  USE  OF  COKE  — 
PROPERTIES  IN  ORES  — OPERATIONS  OF  BLAST 
FURNACES  — THE  DIFFERENT  BRANDS  OF  PIG 
IRON  AND  HOW  TO  PURCHASE  AND  USE  THEM 
INTELLIGENTLY. 

CHAP.  PAGE. 

1.  The  Manufacture  and  Properties  of  Coke, I 

2.  Properties  of  Ores  used  in  Making  Cast  Iron, 25 

3.  Construction  of  Blast  Furnaces, 34 

4.  Lining  and  Drying  Blast  Furnaces, 40 

5.  Operating  Blast  Furnaces  and  Reduction  of  Ores,  ...  46 

6.  Cause  and  Evils  of  Scaffolding  and  Slips  in  Furnaces,  .  55 

7.  Composition  and  Utility  of  Fluxes, 59 

8.  Fluxing  and  Slagging  out  Blast  Furnaces,  .......  63 

9.  Cold  and  Hot  Blast  vs.  Combustion, 70 

10.  Effects  of  Blast  Temperatures  in  Driving  Furnaces,  .   .    74 

11.  Methods  in  Working  Brick  and  Iron  Stoves  in  Creating 

Hot  Blast 79 

12.  Tapping  out  and  Stopping  up  Furnaces  and  Cupolas,  .   .    89 

13.  Moulding  and  Casting  Sand  and  Chilled  Cast  Pig  Iron 

and    Open    Sand    Work, 99 

14.  Making  Chilled  or  Sandless  Pig  Iron  and  its  Advantages,  113 

15.  Utility  of  Direct  Metal  for  Founding, 117 

1 6.  Banking  Furnaces  and  Cupolas, 121 

17.  Constant  and  Changeable  Metalloids  in  Making  Iron,  .   .130 

1 8.  Segregation  of  Iron  at  Furnace  and  Foundry,  .   .    .   .   .  134 

19.  Mixing  Furnace  Casts  of  Pig  Metal  at   Furnaces  and 

Foundry, 139 


IV  TABLE    OF    CONTENTS. 

CHAP.  PAGE. 

20.  Different  Kinds  of  Pig  Iron  Used  and  Definition  of  Brand 

and  Grade, 144 

21.  Grading  of  Pig  Iron  by  Analyses, 148 

22.  Difference  in  Utility  of  Bessemer  from  Foundry  Iron  for 

Making  Castings, 157 

23.  Charcoal  vs.  Coke  and   Anthracite  Irons   and  some  pe- 

culiar brands, ' 160 

24.  The  Deceptive  Appearances  of  Fractures  in  Pig  Iron,  .    .163 
'25.     Impracticability  of  Hardness  Tests  for  Grading  Pig  Iron,  175 

26.  Origin  and  Utility  of  Standardized  Drillings 180 

27.  Intelligent  Purchase  and  Sampling  of  Pig  Iron,  .   .    .   .194 

PART  II. 

ELEMENTS  IN  CAST  IRON  AND  THEIR  PHYSICAL 
EFFECTS  — UTILITY  OF  CHEMICAL  ANALYSES 
AND  HOW  TO  USE  THEM  IN  MAKING  THE  DIF- 
FERENT MIXTURES  OF  IRONS  USED  IN  MAKING 
GRAY  AND  CHILLED  CASTINGS. 

CHAP.  pAGB. 

28.  The  Metallic  and  Non-Metallic  Elements  of  Cast  Iron,  .  202 

29.  Chemical  and  Physical  Properties  of  Cast  Iron,  .....  205 

30.  Affinity  of    Iron    for    Sulphur  and  Its    Strengthening 

Effects, 223 

31.  Effects  of  Adding  Phosphorus  to  Molten  Iron, 226 

32.  Effects  of  Variation  of  Manganese  in  Different  Irons,  .  233 

33.  Effects  of  Variations  of  Total  Carbon  in  Iron, 246 

34.  Evils  of  Excessive  Impurities  in  Iron 249 

35.  Character  of  Specialties  made  of  Cast  Iron, 252 

36.  Methods  for  Calculating  the  Analyses  of  Mixtures,  .   .   .255 

37.  Effects  of  different  Metalloids  on  Chilled  Castings,  .   .   .258 

38.  Mixtures  for  Chilled  Rolls,  Car  Wheels,  etc., 263 

39.  Mixtures  for  Heavy  and  Medium  Gray  Iron  Castings,  .  273 

40.  Mixtures  for  Light  Machinery  and  Stove  Plate  Castings,  281 

41.  Mixtures  for  Dynamos  and  other  Electrical  Work  Cast- 

ings  284 

42.  Mixtures  for  White  Iron  Castings  and  Effects  of  An- 

nealing,    287 

43.  Methods  for  Judging  the  Analyses  of  Scrap  Iron 292 

44.  Analyses  and  Strength  of  Typical  Foundry  Iron  Mixtures,  298 


TABLE    OF    CONTENTS.  V 

CHAP.  PAG*. 

45.  Chemical  Changes  made  in  Iron  by  Remelting  it,  ...  302 

46.  Loss  of  Iron  by  Oxidation  and  Slagging  out, 309 

47.  Comparative  Fusibility  and  the  Melting  Point  of  Differ- 

ent Irons, , 323 

48.  Aluminum  Alloys  in  Cast  Iron, ,   .  357 

PART  III. 

PROPERTIES  OF  AND  METHODS  FOR  TESTING 
MOLTEN  IRON  — DISCLOSES  PHENOMENA  IN  THE 
ACTIONS  OF  COOLING  METAL,  ETC.— PRESENTS 
RESULTS  OF  TESTS  IN  ALL  KINDS  OF  IRONS 
AND  BEST  METHODS  FOR  TESTING. 

CHAP.  PAOB. 

49.  Methods  for  Melting  Iron  to  Test  its  Physical  Qualities,  362 

50.  Judging  of  and  Testing  Molten  Iron, 368 

51.  Effects  of  Variations  in  the  Fluidity  of  Metals, 372 

52.  Specific  Gravity  of  Vertical- Poured  Castings, 377 

53.  Expansion  of  Iron  at  the  Moment  of  Solidification,  .   .   .  382 

54.  Effect  of  Expansion  on  Shrinkage  and  Contraction,  .   .  386 

55.  Stretching  Iron  and  Contraction  Rules, 418 

56.  Utility  of  Chill  Tests,  and  Methods  for  Testing  Hardness,  432 

57.  Utility  of  Transverse,    Crushing,    Impact    Tests,    and 

Testing  Car  Wheels, 439 

58.  Achieving  Uniform  Records  and  Utility  of  Tensile  Tests,  449 

59.  Contraction  vs.  Strength  of  Cast  Iron, 451 

60.  Comparison  of  Strength  in  Specialty  Mixtures, 458 

61.  Computation  of  the  Relative  Strength  of  Test  Bars,  .   .  474 

62.  Value  of  Micrometer  Measurements  in  Testing 478 

63.  Operating  Testing  Machines 481 

64.  Round  vs.   Square  Test  Bars, 483 

65.  Evils  of  Casting  Test  Bars  Flat 488 

66.  Physical  Tests  for  the  Blast  Furnace  and  their  Value,  .  495 

67.  Appliances  and  Methods  for  Casting  Test  Bars, 512 

68.  Moulding,  Swabbing,  and  Pouring  Test  Bars, 523 

69.  Utility  of  the  Test  Bar  —  Standard  Methods  for  Testing,  528 

70.  Methods  of  Casting  and  Compilation  of  Results  of  Amer- 

ican Foundrymen's  Association's  Tests,     ...    ...  539 

71.  A  Process  for  Brazing  Cast  Iron,  and  Etching, 585 


VI  TABLE    OF    CONTENTS. 

SELECTED   TABLES  OF  UTILITY  FOR  FURNACE  AND 
FOUNDRY  WORK. 

TABLK.  PAGE. 

128.  Net  Weight  of  Sand  Pig  per  Ton  of  2,268  pounds,  .   .   .  589 

129.  Net  Weight  of  Chilled  Pig  Iron  per  Ton  of  2,240  pounds,  590 

130.  Chemical  Symbols  and  Atomic  Weights,  .......  591 

131.  Value  in  Degrees  of  Centigrade  for  Each  100  Degrees 

Fahr., 591 

132.  Units  of  Heat  and  Heat  of  Combustion 592 

133.  Scale  of  Temperatures  by  Color  of  Iron, 592 

134.  Melting  Point  of  Metals, 593 

135.  Relative  Conductivity  of  Metals  for  Heat  and  Electricity,  593 

136.  Specific  Gravity  and  Weight  of  Metals,  per  Cubic  Inch  593 

137.  Ultimate  Resistance  of  Metals  to  Tension  in  Pounds 

per  Square  Inch 594 

138.  Strength  of  Different  Kinds  of  Woods, 594 

139.  Decimal  Equivalents  of  Fractions  of  an  Inch, 594 

Index  59s  to  627 


PREFACE    TO    FIRST   AND    SECOND 
EDITIONS.* 


This  work  is  written  with  a  view  to  its  value  not 
only  to  the  founder,  the  moulder,  the  blast  furnace- 
man,  the  chemist,  and  the  engineer,  but  also  to  the 
designer,  the  draftsman,  the  pattern-maker,  the  college 
specialist,  and  all  that  may  in  any  manner  be  desirous 
of  obtaining  a  practical  knowledge  of  cast  iron  in  its 
application  to  founding  or  any  allied  interests.* 

In  compiling  this  volume,  the  author  has  been  guided 
by  a  broad  experience  as  a  moulder  and  founder  in 
loam,  dry,  and  green  sand  work,  in  the  various  special- 
ties of  founding,  all  of  which  require  a  knowledge  of 
the  subject  as  a  whole  in  order  to  arrive  at  correct 
conclusions  on  questions  pertaining  to  cast  iron. 

A  factor  which  has  also  aided  the  author  in 
presenting  this  volume  is  that  of  being  since  1892 
surrounded,  in  his  present  foundry  location,  by  blast 
furnaces,  thus  affording  him  every  opportunity  of 
making  a  close  study  of  modern  furnace  methods  and 
the  principles  involved  in  making  iron.  This  has  also 
enabled  the  author,  as  a  foundryman,  to  determine 
wherein  many  principles  involved  in  furnace  practice 
can  often  be  well  utilized  in  constructing  and  operating 
cupolas,  as  well  as  in  mixing  iron. 

*  Preface  to  Third  Edition  is  found  on  page  xiii. 


Vlll  PREFACE    TO    FIRST    AND    SECOND    EDITIONS. 

In  many  respects  this  work  will  be  found  to  be  in 
advance  of  general  practice,  presenting  many  new 
subjects,  principles,  and  ideas  calculated  to  greatly 
broaden  practical  literature  upon  the  metallurgy  of 
cast  iron,  but  the  author  does  not  advocate  any  meas- 
ures that  have  not  been  thoroughly  tested  by  experience 
or  a  close  study  of  the  subjects  presented.  While  this 
work  will  be  found  largely  the  product  of  the  author's 
own  experience  and  research,  he  has  also  drawn  upon 
the  work  of  others  wherever,  in  his  judgment,  this 
could  in  any  way  prove  of  practical  value  in  giving  a 
completeness  to  the  various  subjects  treated. 

This  work  contains  illustrations  of  valuable  appli- 
ances which  the  author  has  originated  and  upon  which 
he  could  have  secured  patents,  but  believing  the  ad- 
vancement of  founding  best  aided  by  their  being 
given  freely  to  any  that  desire  to  use  them,  all  are  at 
liberty  to  freely  utilize  the  various  improvements 
shown. 

About  a  dozen  of  the  chapters  are  revised  extracts 
of  papers  which  were  presented  by  the  author  before 
the  British  Iron  and  Steel  Institute,  the  American 
Society  of  Mechanical  Engineers,  the  American  Insti- 
tute of  Mining  Engineers,  and  the  Eastern  and  West- 
ern Foundrymen's  Associations.  The  leading  trade 
papers  of  America  and  Europe  are  also  to  be  credited 
with  having  given  first  publicity  to  some  of  the 
author's  writings  herein  presented.  Among  those  to 
be  mentioned  are  the  American  Machinist,  the  Iron 
Age,  the  Iron  Trade  Review,  and  the  Foundry  — 
American  publications;  and  Engineering,  of  London, 
The  Engineer,  of  Glasgow,  and  other  leading  trade 
papers  of  Europe.  To  all  these  associations  and  trade 


PREFACE    TO    FIRST    AND    SECOND    EDITIONS.  IX 

papers  the  author  tenders  his  thanks.  The  encourage- 
ment thus  rendered  has  served  to  stimulate  the 
completion  of  this  work,  which  has  taken  about 
four  years  to  compile,  due  to  the  experiments, 
research,  etc.,  found  necessary  in  order  to  advance  the 
original  information  presented.  The  result  has  been 
to  bring  all  the  author's  writings  on  the  various  sub- 
jects treated  under  one  cover,  giving  to  the  reader  an 
advantage  that  could  not  be  otherwise  obtained. 

The  first  and  second  editions  are  divided  into  four 
parts  (the  third  edition  is  divided  into  three  parts,  as 
explained  in  the  foot-note),  the  first  illustrating  the 
principles  involved  in  a  general  way  in  the  making  of 
iron,  commencing  with  a  very  complete  chapter  on 
coke  and  its  kin,  iron  ore,  followed  by  a  description  of 
furnace  methods  and  principles  which  can  often  be 
well  applied  to  cupola  practice. 

The  second  part  of  the  first  and  second  editions 
treats  of  cupola  practice,  showing  the  latest  improve- 
ments. It  illustrates  all  the  known  methods  for  the 
application  of  "  center  blast,"  accompanied  with 
information  on  cupola  practice  necessary  to  be  used 
with  the  author's  first  two  volumes  to  give  a  complete 
presentation  of  the  subject  up  to  date.* 

The  third  part  in  the  first  and  second  editions  (now 
the  second  part  in  the  third  edition)  is  devoted  to 
instructions  of  chemistry  in  founding,  and  clearly  illus- 
trates the  requirements  of  a  wholly  different  practice 

*  The  chapters  on  cupolas  in  the  second  part  were  all  transferred 
to  "  Moulder's  Text  Book"  after  the  publication  of  the  second 
edition.  This  caused  the  third  edition  to  be  divided  into  three 
parts,  as  shown  by  Table  of  Contents,  also  Preface  to  Third 
Edition,  page  xiii. 


X  PREFACE    TO    FIRST    AND    SECOND    EDITIONS. 

than  has  been  followed  to  about  the  year  1895  by  most 
founders,  namely,  of  judging  pig  iron  for  mixture  by 
its  fracture,  a  quality  which  chemistry  has  proven  to 
be  wholly  impractical.  It  shows  the  founder  following 
such  methods,  why  he  cannot  expect  to  meet  with  other 
than  bad,  undesirable  results  as  well  as  heavy  losses. 
It  teaches  how  the  greatest  possible  economy  and 
desired  ends  in  making  mixtures  are  best  achieved. 
It  also  defines,  for  practical  application  in  the  various 
specialties,"  the  affinity  which  one  chemical  property  or 
metalloid  has  for  another  in  changing  the  character  or 
grade  of  iron,  and  discloses  valuable  information  on 
the  science  of  mixing  and  melting  cast  iron. 

The  fourth  part  of  the  first  and  second  editions  (now 
the  third  part  of  the  third  edition)  is  devoted  to  the 
subject  of  testing,  and  discloses  new  discoveries  made 
by  the  author  which  explain  causes  for  erratic  results 
heretofore  obtained  for  the  most  part  from  trans- 
verse and  tensile  tests,  contraction  chill,  etc.,  recorded 
from  bars  of  like  area  poured  from  the  same  ladle 
and  gate,  and  presents  methods  best  calculated  to 
reduce  erratic  results  to  the  least  possible  mini- 
mum. 

Following  the  seventieth  chapter  (seventy-first  chap- 
ter, third  edition),  the  work  is  closed  with  a  few  tables 
and  an  index.  The  first  table  gives  the  net  weight  of 
pig  iron  in  gross  tons  of  2,268  pounds,  ranging  from 
one  to  one  hundred  tons.  (The  third  edition  gives  a 
table  of  2,240  pounds  for  figuring  chilled  pig.)  The 
second  table  presents  the  full  names  of  chemical  prop- 
erties in  metal,  accompanied  with  their  abbreviations 
or  symbols  as  generally  written  by  chemists.  The 
tables  following  are  copied  from  Messrs.  Cremer  and 


PREFACE    TO    FIRST    AND    SECOND    EDITIONS.  Xl 

Bicknell's  "  Handbook  for  Chemical  and  Metallurgical 
Practice. ' ' 

It  is  not  intended  that  this  preface  shall  convey  a 
complete  statement  concerning  the  importance  of  all 
the  subjects  treated.  In  order  to  obtain  further  con- 
ception of  the  important  subjects  discussed  in  the 
various  parts  of  the  work,  the  reader  is  kindly  referred 
to  a  close  study  of  the  table  of  contents. 

THOS.  D.  WEST. 

SHARPSVILLE,  PA.,  Jan.  5,  1897. 


PREFACE  TO  THIRD  EDITION. 


A  comparison  of  this  third  edition  with  the  two  pre- 
vious ones  shows  that  this  work  has  been  extensively 
revised  and  enriched  by  the  addition  of  much  new 
matter  on  making,  mixing1,  melting  and  testing  of 
cast  iron,  part  of  which  constitutes  twenty  new  chap- 
ters embodying  researches,  experiences,  experiments, 
discoveries,  and  illustrations  that  have  been  secured 
by  the  author  since  the  publication  of  the  first  edition 
in  1897.  To  provide  space  for  this  large  addition  of 
new  matter  thirteen  chapters  treating  of  cupola  prac- 
tice, published  in  the  first  two  editions,  have  been 
transferred  to  the  "Moulder's  Text  Book,"  leaving 
this  work  to  the  treatment  of  subjects  more  appropriate 
to  its  title,  dividing  the  third  edition  into  three  parts 
instead  of  four,  as  in  the  first  and  second  editions. 
For  information  on  the  special  subjects  treated  in  this 
work,  readers  are  referred  to  the  preface  of  first  and 
second  editions  which  precedes  this,  and  also  retained 
as  originally  written  to  assist  in  illustrating  the  changes 
made  in  the  third  edition. 

The  author's  original  researches,  experiments,  and 
discoveries  described  in  this  work  involved  an  out- 
lay of  much  time  and  money,  and  he  is  indebted  to  a 
number  of  individuals  for  their  valuable  assistance  in 
making  chemical  analyses,  etc. ,  and  who  have  received 


XIV  PREFACE    TO    THIRD    EDITION. 

proper  credit  throughout  the  work.  The  melting1  and 
physical  testing  was  chiefly  done  by  the  author,  or 
under  his  supervision,  as  he  advocates  that  all  inves- 
tigators should  do  their  own  experimenting  or  other 
work  as  far  as  possible. 

There  are  a  few  works,  in  almost  all  epochs,  that  are 
so  original  and  in  advance  of  the  times  in  their  treat- 
ment and  advocacy  of  new  methods  and  suggested 
improvements,  that  it  requires  a  lapse  of  several  years 
to  test  their  utility.  The  sales  of  some  never  exceed 
their  first  edition,  while  others,  by  force  of  merit,  live 
and  are  recognized  as  standards,  receiving  much  credit 
for  their  utility  and  praise  for  the  benefits  they  render. 
This  work  belongs  to  the  latter  class  and  has  met  with 
a  success  that  is  very  gratifying,  as  the  reforms  and 
new-school  practices  of  mixing  metals,  by  utilizing 
chemistry,  testing,  etc.,  advanced  by  the  author  in 
the  first  two  editions  are  to-day,  1901,  adopted  and 
highly  praised  by  a  large  number  of  those  interested  in 
the  making  and  use  of  cast  iron.  About  25  per  cent. 
of  our  present  founders  still  follow  the  old-school 
practices,  and  to  further  influence  some  toward  an 
adoption  of  the  methods  advanced  in  this  work  the 
author  is  pleased  to  present  the  following  extracts 
seen  on  the  next  two  pages  from  a  few  of  many  testi- 
monials tendered  him  during  the  year  1901. 

SHARPSVILLE,  PA.,  October,  1901.  THOS.    D.   WEST. 


ISSUE  OF  FOURTH  EDITION. 

Preannouncement  of  the  issue  of  the  third  edition  so 
rapidly  exhausted  it,  that  this  fourth  edition  was  found 
necessary  before  trade  papers,  etc.,  could  announce 
and  review  the  third  edition.  THOS  D  WEST 

SHARPSVILLE,  PA.,  January,  1902. 


PREFACE    TO  FIFTH    EDITION. 


The  firct  edition  of  this  work,  which  can,  in  its 
present  form,  be  justly  called  a  practical  compilation  of 
original  research,  was  issued  sooner  than  it  would  have 
been,  had  not  the  author  been  anxious  to  combat  and 
thwart  impractical  theories  and  practices  that  some  in- 
experienced in  general  founding  were  laboring  to 
establish,  and  which  can  be  found  in  past  records  of 
trade  papers  and  engineering  societies,  etc.,  and  are 
now  proven  to  be  incorrect.  The  original  information 
and  reforms  advanced  in  this  work  were  too  far  in  ad- 
vance of  the  times  to  escape  severe  criticism  or  insure 
the  popular  support  they  were  entitled  to,  but  are  now 
receiving  in  such  measure  as  to  be  very  gratifying  to  the 
author.  The  impractical  theories  and  practices  that 
were  advanced  are  not  yet  all  set  aside  or  acknowledged 
to  be  wrong  and  injurious  as  they  shoul'd  be  by  their 
advocates.  However,  the  exhaustion  of  the  third  and 
fourth  editions  of  this  work  in  the  short  period  of  two 
months  is  a  strong  endorsement  of  the  original  practices, 
reforms,  etc.,  advanced,  and  its  practical  utility.  Time 
will  demonstrate  to  all  those  not  yet  convinced  of 
the  impracticability  of  past  teachings  what  is  correct. 

Not  only  does  the  large  sale  of  this  work  demon- 
strate its  growing  popularity,  but  also  forcibly  illus- 
trates the  advancement  of  founders  to  accept  its 


XVI  PREFACE    TO    FIFTH    EDITION. 

advocacy  of  chemical  analyses,  etc.,  in  mixing  metal 
instead  of  judging  pig  iron  by  the  appearance  of  its 
fracture.  One  class  of  castings  (ingot  moulds)  made 
by  the  firm  of  which  the  author  is  the  manager,  is 
subjected  to  the  most  rigid  tests,  when  in  use,  that 
castings  can  be  put  to.  In  making  these  castings,  an 
excellent  opportunity  is  afforded  to  test  the  utility  of 
working  by  chemical  analyses.  There  are  about  half 
a  dozen  ingot  mould  makers  in  the  United  States  and 
all  of  them  will  agree  with  the  author  when  he  asserts 
that  being  guided  by  chemical  analyses  instead  of  pig 
iron  fractures  has  increased  the  efficiency  of  ingot 
mould  service  over  fifty  per  cent.  Manufacturers  of 
other  lines  of  castings  can  find  similar  and  other 
benefits  by  the  adoption  of  chemistry  and  following 
the  teachings  of  this  work.  We  have  other  works  and 
writings  showing  effects  of  the  carbons,  silicon,  sulphur, 
manganese,  phosphorus,  etc. ,  in  changing  the  character 
of  iron,  but  they  fail  in  not  setting  forth  essentials  that 
must  be  followed  in  order  to  make  chemistry  a  success  in 
founding  or  insure  the  greatest  certainty  and  economy 
in  obtaining  desired  mixtures  of  iron.  The  work  has 
been  said  to  be  too  large ;  but  not  until  certain  imprac- 
tical theories  and  practices  have  been  entirely  set  aside 
can  it  be  abridged  or  parts  cut  out. 

About  one  month  after  the  issue  of  the  third  edition 
of  this  work  Mr.  W.  J.  Keep  brought  out  a  book  entitled 
"  Cast  Iron,"  published  by  John  Wiley  &  Sons,  New 
York.  On  page  129  of  this  work  he  refers  to  a  report 
made  by  a  committee  of  the  Western  Foundrymen's 
Association,  in  which  preference  was  given  to  square 
bars  cast  flat  instead  of  round  bars  cast  on  end,  which 
had  fluidity  strips  and  chill  attached  to  them.  This 


PREFACE    TO    FIFTH    EDITION.  •  XV11 

was  due  to  the  lack  of  skill  on  the  part  of  the  molders 
and  their  inexperience  in  making  such  round  bars  on 
end.  Why  does  Mr.  Keep  refer  to  the  Chicago 
foundrymen's  local  Association  report  and  not  to  that 
of  the  national  body  (American  Foundrymen's  Asso- 
ciation), accepted  at  Buffalo,  June  1901,  in  which 
they  recommend  the  use  of  round  bars  cast  on  end,  and 
that  bars  should  not  be  smaller  than  i  ^  inches  diameter, 
as  recorded  on  pages  574  to  584  of  this  work,  and 
also  still  persist  in  advocating  the  use  of  j^-inch 
square  bars  with  the  evidence  obtainable  to  prove  their 
unfitness  for  testing  cast  iron.  Good  evidence  of  the 
unfitness  of  ^2 -inch  square  bars  is  presented  by  Mr. 
Keep  in  his  book,  "  Cast  Iron, "  pages  173  and  174. 
Here  we  find  that  a  slight  difference  in  the  fluidity 
of  the  same  metal  gave  a  difference  of  a  hundred 
pounds  in  the  body  of  two  ^-inch  square  bars  —  a 
quality  exactly  in  keeping  with  the  evidence  pre- 
sented in  this  work  —  showing  how  easily  such  small 
bars  are  made  unreliable  by  slight  variations  in  the 
temper  or  dampness  of  molding  sand  and  temperature 
of  pouring  metal. 

Mr.  Keep  has  presented  tests  in  his  work  that  were 
obtained  by  the  American  Foundrymen's  Association 
committee,  but  in  so  doing  endeavors  to  carry  along 
tests  of  the  ^-inch  bar  also.  The  A.  F.  A.  com- 
mittee found  that  a  bar  as  small  as  )4  -inch  square  or 
round  was  wholly  unsuited  to  test  any  kind  of  iron, 
and  hence  totally  ignored  it  in  their  recommendation, 
which  was  unanimously  accepted  by  this  national 
body,  as  stated  above.  It  is  to  be  regretted  that  men 
of  inexperience  in  the  actual  work  of  broad  molding 
or  founding  may  be  led  to  adopt  incorrect  practices, 


XV111  PREFACE    TO    FIFTH    EDITION. 

and  that  the  general  adoption  of  correct  methods  for 
testing  cast  iron  is  to  be  retarded  by  the  advocacy  of 
such  an  unreliable  and  impractical  test  bar  as  the 
^-inch  square. 

The  author  would  not  have  embodied  these  remarks 
in  a  preface,  did  he  not  feel  that  events  warranted  them 
and  he  trusts  it  may  be  the  means  of  doing  some  good  in 
assisting  to  abolish  an  impractical  and  injurious 

practice. 

THOS.   D.   WEST. 

SHARPSVILLE,  PA.,  February,  1902. 


PREFACE  TO  SEVENTH  EDITION. 

During  the  period  intervening  the  publication  of  the 
revised  third  and  the  sixth  editions,  the  demand  has 
been  such  as  to  allow  no  time  to  make  changes  in  the 
plates.  Thus,  a  few  errors  remained  in  the  revised 
work  until  the  seventh  edition  went  to  press.  The  few 
errors  found,  however,  were,  I  am  pleased  to  say,  of 
such  a  character  as  not  to  injure  the  practical  value  of 
the  work. 

The  appreciation  expressed  by  reviewers  who  have 
recommended  this  work  to  the  public  through  the 
press,  and  by  individuals,  has  done  much  to  increase 
its  popularity.  I  am  not  disregardful  of  these  compli- 
ments tendered  my  work,  and  wish  here  to  thank  all 
those  who  have  interested  themselves  in  its  behalf. 

THOS.   D.  WEST. 

SHARPSVILLE,  PA.,  June,  1902. 


COMMENTS. 


Mr.  W.  G.  Scott,  Metallurgist  and  Chemist  for  J.  I. 
Case  T.  M.  Company,  Racine,  Wis.,  and  laboratories 
at  Philadelphia,  Chicago,  and  Milwaukee,  says  of 
'  *  Metallurgy  of  Cast  Iron  " :  "  Nearly  every  foundry- 
man  has  this  work,  and  I  believe  that  it  has  done  more 
to  advance  the  science  of  founding  than  any  work  ever 
published.  Since  the  appearance  of  this  book  there 
has  been  a  notable  change  in  foundry  practice.  The 
number  of  firms  now  mixing  by  analyses  is  astonish- 
ing, and  I  think  that  its  author  is  entitled  to  the  credit 
of  starting  the  greater  part  of  them  on  the  modern 
plan,  i.e.,  chemical  metallurgy.  I  cannot  say  too  much 
in  praise  of  this  book. ' ' 

Mr.  Frank  L.  Crobaugh,  Proprietor  and  Expert,  The 
Foundrymen's  Laboratory,  Cleveland,  O.,  and  author 
"  Methods  of  Chemical  Analyses  and  Foundry  Chem- 
istry ' '  says :  "  *  The  Metallurgy  of  Cast  Iron  '  has 
caused  many  advances  in  foundry  practice,  including 
the  application  of  chemistry. ' ' 

Mr.  Edgar  S.  Cook,  President  and  General  Manager 
of  The  Warwick  Iron  &  Steel  Co.,  Pottstown,  Pa., 
says:  "  I  frequently  hear  the  most  complimentary 
remarks  in  regard  to  the  beneficial  influence  of  Mr. 
West's  papers,  and  especially  with  reference  to  his 
*  Metallurgy  of  Cast  Iron. '  There  is  evidently  a  strong 
desire  on  the  part  of  all  interested  in  the  subject,  blast 


XX  COMMENTS. 

furnace  managers  as  well  as  progressive  foundrymen, 
to  arrive  at  some  formula  whereby  guesswork  may  be 
replaced  by  certain  well  determined  facts,  and  thus 
afford  a  safe  foundation  for  scientific  methods  in 
foundry  practice.  Mr.  West's  efforts  in  this  direction 
are  deserving  of  the  widest  recognition. ' ' 

Mr.  E.  H.  Putnam,  Foundry  Superintendent,  Moline, 
111.,  and  editor  of  the  foundry  department  of  The 
Tradesman,  Chattanooga,  Tenn.,  in  writing  of  "  Metal- 
lurgy of  Cast  Iron  ' '  says :  "I  am  glad  to  attest  my 
appreciation  of  its  great  practical  value.  It  is  unsur- 
passed in  foundry  literature,  and  is  an  invaluable 
adjunct  to  the  foundryman's  library." 

Mr.  Francis  Schumann,  the  first  president  of  the 
American  Foundrymen 's  Association,  says:  "  The 
foundry  industry  owes  a  lasting  tribute  to  Thomas  D. 
West  for  his  efforts  towards  more  comprehensive  and 
rational  methods  in  its  processes.  Mr.  West  holds  the 
singular  position  of  a  foundryman  engaged  in  the 
actual  practice  of  his  art,  who,  with  ability,  enthusi- 
asm, and  zeal  in  original  research  imparts  the  knowl- 
edge so  obtained  freely  and  without  reward.  Much 
information  is  contained  in  his  work  of  '  Metallurgy  of 
Cast  Iron  '  which  cannot  fail  to  interest  foundrymen 
and  engineers,  touching,  as  it  does,  upon  every  stage 
from  melting  to  the  test  bar.  The  work  is  of  a  kind 
that  can  come  only  from  the  practical  founder  about 
matters  seldom  found  in  print,  because  practical  foun- 
drymen of  Mr.  West's  attainments  are,  as  yet,  a  rarity. *" 


PART  I. 


CHAPTER  I. 

THE    MANUFACTURE    AND    PROPERTIES 
OF  COKE. 

The  chemical  and  physical  properties  of  fuel, having 
much  to  do  with  the  physical  and  chemical  properties 
of  cast  iron,  when  made  or  remelted,  the  author  has 
thought  that  a  general  article  on  this  subject  would  be 
very  fitting  in  this  work.  Coke  was  first  successfully 
used  in  this  country  at  the  Clinton  Furnace,  in  Pitts- 
burg,  in  1860.  Prior  to  this  anthracite  and  bituminous 
coal,  also  charcoal,  had  been  almost  wholly  used  for 
smelting  in  furnaces;  while  anthracite  coal  was  the 
chief  fuel  used  by  founders.  In  changing  from  the 
use  of  anthracite  coal  to  coke  for  making  and  remelting 
iron,  Pennsylvania  and  Ohio  took  the  lead.  It  wa*s 
not  long  until  its  use  increased  to  such  a  degree  that 
few  are  now  found  in  this  country  depending  on  coal 
entirely  as  a  fuel  for  making  and  remelting  iron.  Coke 
has  forced  its  adoption  for  making  iron  mainly  because 
it  is  a  cheaper  fuel,  and  for  remelting  iron  because, 
aside  from  cheapness,  it  requires  less  blast  and  melts 
more  quickly  than  coal.  Coal,  however,  has  still  some 
advantages  for  remelting  iron. 

The  process  of  making  coke  consists  of  taking  soft  or 
bituminous  coal  and  letting  it  burn  for  a  number  of 
hours  in  what  are  called  coke  ovens,  generally  of  the 
form  seen  in  Fig.  i.  Other  forms  and  methods  are 


4          .  METALLURGY    OF    CAST    IRON. 

used,  and  some  of  them  are  covered  by  patents.  Some 
of  the  advantages  claimed  for  patent  ovens  are  in  the 
recovery  of  by-products  and  in  saving  labor  and 
obtaining  a  greater  yield  of  coke  from  the  same  amount 
of  coal. 

The  main  principle  in  coking  lies  in  admitting  the 
air  to  support  combustion  at  or  over  the  surface, 
instead  of  causing  it  to  pass  through  the  coal  as  in 
burning  fuel  for  firing  boilers,  etc.,  thus  being  an 
action  of  distillation  more  than  of  combustion.  This 
prevents  destruction  of  the  coal  while  burning,  and 
causes  it  to  '  *  cake  ' '  and  become  the  coke  of  industrial 
commerce. 

The  kind  of  ovens  generally  used  in  America  is  the 
bee -hive  oven,  as  illustrated  in  Fig.  i,  page  8.  Ovens 
are  generally  built  from  ten  and  one -half  to  twelve 
feet  in  diameter  and  from  five  to  eight  feet  in  height. 
The  standard  size  is  twelve  feet  in  diameter  and  from  six 
to  eight  feet  high.  Some  are  built  on  the  plan  seen  in 
Fig.  i.  The  interior  of  the  oven  is  fire-brick,  and  the 
space  between  the  ovens  is  packed  with  clay  or  loam- 
Pillars,  as  at  K,  are  used  for  the  support  of  the  larries 
on  the  track  B,  so  as  to  take  their  weight  from  the  arch 
of  the  ovens.  The  outside  of  the  ovens,  as  at  S,  are 
built  of  stone  and  made  very  strong.  The  filling  is 
clay  or  loam,  and  the  floor  X  is  composed  of  tile 
fire-brick. 

Coal  is  sometimes  coked  in  mounds,  heaps,  or  piles 
similar  to  the  method  used  for  making  charcoal  of 
wood.  It  was  by  such  method  that  coke  was  first 
made.  By  such  methods  of  coking  the  coal  must  be 
chiefly  in  lumps,  and  piled  in  such  a  manner  as  to 
leave  all  the  air  space  that  is  practical  through  the 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE.  5 

body  of  the  mounds,  and  also  piled  so  as  to  have  as 
little  of  it  touch  the  ground  as  possible.  The  mounds 
or  piles  are  generally  built  around  a  brick  chimney  laid 
with  loose  bricks,  left  as  full  of  holes  in  every  other 
course  of  bricks  as  is  practical,  so  as  to  provide  open- 
ings for  draft  from  the  outside  of  the  mounds  at 
various  heights.  These  piles  range  from  fifteen  to 
thirty  feet  in  diameter,  and  from  four  to  seven  feet 
in  height.  They  are  set  on  fire  by  means  of  openings 
left  in  their  bodies  where  wood  and  light  brush  can  be 
inserted.  Some  piles  are  built  in  an  oblong  form, 
often  running  two  hundred  feet  or  more  in  length,  with 
a  base  of  twelve  to  fifteen  feet  in  width.  The  plan  of 
building  such  long  piles  is  to  lay  a  body  of  coal  about 
sixteen  inches  high,  then  commence  the  formation  of 
flues  as  seen  in  C,  Fig.  2,  page  10.  These  flues  are 
filled  with  wood,  brush,  or  any  light  kindling,  and 
then  set  on  fire  at  every  opening,  the  aim  being 
that  no  one  part  of  the  pile  burn  faster  than  another. 
If  the  fire  should  be  too  strong  at  any  one  point,  the 
outside  surface  is  banked  with  wet  coke  dust  or  earth, 
and  applied  to  the  whole  surface  of  the  structure  as 
soon  as  the  volatile  matter  has  stopped  burning  so  as 
to  smother  the  fire  and  complete  the  coking  of  the  coal. 
The  last  operation  in  this  method  of  coking  is  to  pour 
a  little  water  down  the  vertical  flues  so  as  to  diffuse 
steam  throughout  the  entire  body  of  the  coke,  which  it 
is  claimed  is  beneficial,  resulting  in  the  least  moisture 
in  the  coke.  It  takes  from  five  to  eight  days,  accord- 
ing to  the  state  of  the  weather,  to  perfect  coking  by 
this  plan.  The  coke  produced  is  said  to  be  of  very 
good  quality,  but  as  a  general  thing  there  is  a  consider- 
able loss  in  the  yield  where  coal  is  coked  in  mounds  or 


6  METALLURGY    OF    CAST    IRON. 

heaps,  and  the  method  has  the  disadvantage  of  requir- 
ing the  coal  to  be  in  lump  form.  It  is  only  where  it  is 
costly  to  secure  building  material,  or  where  the  coking 
qualities  of  coal  are  to  be  tested  before  expensive  ovens 
are  erected  that  mounds  are  used  to  coke  coal  at  the 
present  time. 

Coke  has  been  found  in  a  natural  state.  Appleton's 
Encyclopedia  cites  a  bed  existing  on  both  sides  of  the 
James  River  and  near  Richmond,  Va.  It  is  said  to  be 
hard,  very  uniform,  and  dark  in  color,  but  rather 
porous.  It  is  claimed  to  be  serviceable  for  melting 
purposes. 

By-product  coke  ovens  have  been  erected  by  some 
firms  owning  steel  plants,  etc.,  whereby  they  can 
make  their  own  coke  at  their  works  or  at  the  mines. 
By  this  process,  in  connection  with  the  by-products, 
such  as  gas,  tar,  and  other  substances  produced,  it  is 
claimed  they  can  make  a  good  profit  on  money  invested 
and  also  be  independent  of  the  regular  coke  manufac- 
turers. It  is  said  that  out  of  one  ton  of  coal  ten  thou- 
sand feet  of  gas  can  be  produced,  and  out  of  fifteen 
hundred  pounds  of  coke  ninety  to  one  hundred  pounds 
of  tar,  with  other  by-products,  can  be  produced.  The 
gas  from  such  ovens  could  prove  of  much  value  to 
some  founders  in  drying  moulds,  cores,  etc. ,  and  run- 
ning boilers.  What  coke  the  author  has  seen  and  used 
coming  from  by-product  ovens  is  not  as  solid  as  the 
regular  Connellsville  coke,  and  it  required  a  greater 
percentage  of  it  to  melt  iron. 

In  charging  the  bee-hive  ovens  enough  coal  is  gen- 
erally carried  by  one  larrie,  A,  to  fill  an  oven  at  one 
charge.  This  larrie  runs  on  a  track  over  the  top  of 
the  oven,  as  shown  at  B,  Figs,  i,  3,  and  4.  The  latter 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE.  7 

two  cuts  are  from  an  article  by  Mr.  W.  G.  Irwin  in 
Gassier 's  Magazine,  January,  1901.  The  amount  of 
coal  charged  into  a  bee-hive  oven,  as  described  here- 
with, covers  the  floor  to  a  depth  of  about  two  feet  for 
48 -hour  coke,  and  two  and  a  half  feet  for  7  2 -hour  coke, 
and  in  weight  ranges,  according  to  the  diameter  of  the 
oven,  from  three  and  one-half  to  six  and  one-half  tons. 
By  a  handy  dumping  arrangement,  the  coal  may  be 
delivered  to  the  ovens  on  either  side  of  the  track. 
After  the  coal  has  been  dumped  into  the  ovens  through 
the  hole  E,  it  is  leveled  by  means  of  a  long-handled 
hook  worked  through  the  door  at  D.  This  done,  the 
door  is  partially  closed  by  means  of  bricks  loosely  laid 
and  luted  with  clay  or  loam,  an  opening  of  about  three 
inches  being  left  at  the  top  of  the  door  for  the  admis- 
sion of  air  to  support  combustion  in  the  oven.  As  the 
coking  progresses  the  opening  for  the  admission  of  air 
is  gradually  made  less  and  eventually  closed,  in  con- 
nection with  the  charging  opening  E,  should  the  oven 
be  carried  over  or  burn  off  too  soon. 

The  coal  is  ignited  by  the  heat  which  the  ovens 
retain  from  the  previous  coking.  A  sharp  draft  is 
admitted  as  soon  as  the  coal  is  ignited,  which  is  about 
an  hour  after  it  is  charged.  A  black  smoke,  combined 
with  a  greenish  colored  gas  and  occasional  outbursts  of 
flame,  passes  up  through  the  charging  hole  E,  which 
is  left  open  to  create  a  draft  and  permit  the  escape  of  all 
smoke  and  gases  that  may  emanate  from  the  coal.  The 
gas  which  escapes  has  an  odor  sometimes  strong  of 
sulphur.  The  smoke  generally  ceases  ten  to  twelve 
hours  after  the  first  ignition  of  the  coal,  after  which  a 
bright  flame  passes  through  the  opening  E  and  covers 
the  entire  surface  of  the  coal,  which  by  this  time  has 


\ 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE.  9 

attained  almost  a  white  heat.  This  process  continues 
until  the  bright  flame  dies  out,  and  then  the  coke  is 
simply  a  red-hot  mass  containing-  not  much  more  than 
one  per  cent  of  the  volatile  matter  originally  in  the 
coal,  the  greater  balance  having  passed  off  during  the 
time  in  which  the  body  of  coal  was  raised  to  its 
highest  temperature. 

When  the  48=  and  72-hour  coking  period  is  com- 
pleted, or  the  oven  is  "around,"  a  stream  of  water 
from  a  hose  (or  the  water  may  be  thrown  from  buckets) 
is  sent  over  the  surface  of  the  glowing  mass  to  extin- 
guish the  fire.  It  is  very  important  to  cool  off  or  stop 
all  further  combustion  at  this  point  of  the  coking,  as, 
if  permitted  to  continue  burning,  carbon  would  be 
consumed,  thus  causing  a  material  loss  of  coke. 

Before  drawing  the  coke,  it  is  partly  or  wholly  cooled 
off  with  water.  The  coal  as  it  lies  ' '  caked, ' '  or 
* '  coked, ' '  after  being  cooled  in  one  solid  mass,  is  full 
of  vertical  seams  or  cracks  caused  by  the  contraction. 
The  cokers  insert  their  hooks  in  these  seams  in  draw- 
ing the  coke  from  the  ovens.  It  is  landed  on  the  coke 
wharves  H,  Fig.  i,  from  which  it  is  loaded  into  cars 
standing  on  the  track  R  and  shipped  broadcast  to 
consumers,  a  perspective  view  of  which  is  seen  in 
Figs.  3  and  4,  pages  12  and  21.  The  care  exercised  and 
the  time  taken  in  drawing  the  coke  from  the  ovens  has 
much  to  do  with  its  size,  freedom  from  ' '  braize, ' '  or 
small  coke,  and  the  yield.  Soon  after  the  coke  has 
been  withdrawn,  the  oven  is-  again  filled  with  a  charge 
of  coal,  the  drawing  door  closed,  and  the  heat  of  the 
oven  from  the  previous  coking,  as  above  stated,  ignites 
the  fresh  coal  and  the  coking  process  is  again  started. 
Some  manufacturers  have  followed  the  practice  of 


^^«ss  Sect^n, 


Ground  Flan. 
FIG.    2. — COKING  IN   MOUNDS. 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE.          II 

drawing  the  coke  from  the  ovens  before  cooling  it  off 
with  water.  The  method  of  cooling  the  coke  on  the 
inside  is  hard  on  the  brick  composing  the  interior,  but 
it  makes  a  brighter  coke  and  more  comfortable  work 
for  the  cokers.  In  so  far  as  it  relates  to  the  question 
of  moisture  in  coke,  the  product  absorbs  less  moisture 
when  cooled  off  in  the  inside  than  outside  of  the  ovens. 

Some  coke  holds  water  to  the  extent  of  fifteen,  to 
twenty  per  cent  of  its  own  weight.  Good  fresh  coke 
should  not  possess  much  over  one  per  cent  of  moisture 
when  protected  from  rain  and  snow.  As  it  takes  about 
fifteen  pounds  of  coke  in  a  cupola  to  evaporate  one 
pound  of  water,  it  is  evident  that  the  less  moisture  a 
coke'  contains  the  less  fuel  required  in  melting,  etc. 
Some  firms  recognize  this  factor  and  build  stock  houses 
so  as  to  keep  coke  under  cover.  It  is  claimed  that 
exposing  coke  to  outdoor  weather  will  reduce  sulphur. 
To  what  extent  this  is  true  has  never  been  demon- 
strated. 

Coal  is  sometimes  of  such  poor  quality,  or  full  of 
slate  or  iron  pyrites,  that  it  must  undergo  a  process 
of  washing  before  it  can  be  charged  into  the  oven  to 
be  coked.  The  method  of  treatment  consists  in  crush- 
ing the  coal,  if  it  is  in  lump  form,  so  as  to  make  it  as 
fine  as  slack.  It  is  then  carried  by  means  of  buckets 
attached  to  an  endless  chain  from  *boat,  car,  or  crushers 
to  tubs  of  water,  so  arranged  with  "  jiggers  "  that  a 
constant  agitation  and  flow  of  water  causes  the  differ- 
ent bodies  in  the  coal  to  take  their  place  in  the  water 
according  to  their  several  specific  gravities.  The 
pyrites  and  slate,  being  heaviest,  sink  to  the  bottom, 
and  by  a  series  of  jogging  tubs  through  which  the  coal 
is  passed,  the  floating  bodies  —  the  coal  partially  freed 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE. 


from  its  pyrites  and  slate  —  are  caught  by  perforated 
iron  buckets  on  an  endless  chain  and  carried  to  a  stock 
pile  or  to  the  larries,  then  to  the  ovens  to  be  charged 
for  coking.  The  impurities  in  the  form  of  slate  and 
iron  pyrites  which  have  sunk  to  the  bottom,  are  passed 
along  through  the  shutes  with  outflowing  ^water  to  the 
refuse  bed.  The  washing  process  often  removes 
bitumen  with  the  slate  to  such  a  degree  as  to  rob  the 
coal  greatly  of  its  coking  qualities. 

The  yield  of  coke  obtained  from  ovens  generally 
ranges  from  sixty  to  seventy  per  cent  of  the  coal 
charged,  whereas  the  yield  from  heaps  or  mounds 
does  not  exceed  fifty  to  fifty-five  per  cent.  The  long 
mounds  are  said  to  be  productive  of  better  coke  and 
furnish  a  larger  yield  than  round  or  small  oblong  piles 
having  one  center  draft  provision.  The  following  table 
No.  i  shows  the  yield  of  a  few  grades  of  Connells- 
ville  coke  in  ovens  prepared  by  Mr.  John  Fulton,  and 
published  in  the  American  Manufacturer  of  February 
10,  1893: 

TABLE  I. — YIELD  OF  COKE  FROM  COAL. 


, 

i 

• 

Per  cent,  of  yield. 

1 

8 

0    . 

fj 

bo 

•o 

X    . 

o 

o   . 

V 

*; 

^ 

"*  C 

C 

r^ 

CJ  T3 

<U  rrt 

*r1 

o 

<U    QJ 

u 

s 

o 

o  <u 

A 

44  rt 

y 

is 

II 

.C 

C  Q 

la 

ja 

«B 

33 

-"  8 

5 

H 

0 

5 

s 

3 

H 

< 

s 

H 

0< 

h.  m. 

lb. 

lb. 

lb. 

lb. 

lb. 

i 

2 

67    oo 
68    oo 

12,420 
11,090 

99 
90 

385 
359 

6,'58o 

7,903 
6,939 

00.80 
00.81 

3.10 
3-24 

60.53 

59-33 

63-63 
62.57 

35-57 
36.62 

3 

45    °o 

9,120 

77 

272 

5.418 

5,690 

00.84 

2.98 

59-41 

62.39 

36.77 

4 

45    oo 

9,020 

74 

349 

5-334 

5,683 

00.82 

3-87 

59-13 

63.00 

36.18 

41,650 

340 

1,365 

24,850 

26,215 

00.82 

3-28 

59-66 

62.94 

36-24 

The  question  of  density  in  coke  is  largely  one  of  cell 
space,  which  can  vary  greatly  in  hard  as  well  as  in 
soft  grades  of  coke.  Oven  coke  is  generally  considered 


14  METALLURGY    OF    CAST    IRON. 

to  have  a  cell  structure  of  about  fifty  per  cent  greater 
than  exists  in  coal.  The  quality  of  hardness  is  one  of 
much  importance,  especially  in  blast  furnace  practice, 
as  the  coke  should  possess  a  certain  strength  to  sustain 
the  weight  of  the  stock  which  is  charged  on  top  of  it. 
If  it  is  not  strong  enough  to  resist  the  load,  it  can  be 
crushed  into  a  mass  so  compact  as  to  prevent  the  free 
passage  of  blast  through  its  body,  which  is  necessary 
to  create  proper  combustion  and  make  the  furnace 
work  well.  To  a  degree  it  has  the  same  effect  on 
passage  of  blast  in  cupolas.  Then  again  a  soft  coke 
can  crush  so  as  to  lower  a  bed,  cause  dull  iron,  and 
make  a  cupola  bung  up  much  more  readily  than  hard 
coke.  (See  close  of  chapter.)  Oven  coke  can  be  light 
and  porous  as  well  as  heavy  and  dense,  and  is  often 
spoken  of  as  hard  or  soft.  The  terms  hard  and  dense 
do  not  mean  the  same  thing.  Coke  can  be  dense  but 
soft.  The  following  table,  No.  2,  of  physical  tests,  by 
Mr.  John  Fulton,  will  illustrate  the  crushing  strength 
of  coke  with  other  properties.  A  chemical  analysis  of 
the  same  coke  by  Mr.  A.  S.  McCreath  and  Mr.  T.  T. 
Morrel  is  seen  in  Table  3,  and  which  is  taken  from  an 
article  by  the  late  Joseph  D.  Weeks  of  Pittsburg, 
which  appeared  in  the  Pennsylvania  Annual  Report  of 
the  Secretary  of  Internal  Affairs,  1893.  In  referring 
to  the  coke  tested,  Mr.  Fulton  says:  "  These  tests 
show  a  compact,  hard-bodied  coke,  harder  than  the 
average  Connellsville  standard.  This  coke  has  been 
carefully  prepared  and  cannot  be  distinguished  from 
Connellsville  coke.  The  cells  are  a  little  less  than  the 
Connellsville,  but  the  difference  is  not  large  enough  to 
induce  any  marked  change  in  blast  furnace.  It  has 
proved  an  excellent  fuel  for  this  and  kindred  uses. 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE. 


Table  4  is  an  average  of  several  analyses  of  coke  from 
the  Connellsville  region.  The  author  has  used  this 
coke  extensively  at  his  foundry  and  has  found  it  to  be 
a  fair  grade  of  coke. 

TABLE    2. — PHYSICAL   TESTS    OF    SEVENTY-TWO    HOUR    COKE. 


•| 

a, 

3 

*5 

« 

0 

in 

• 

.5 

u 

^    . 

<L»-    . 

0 

2 

^  ^     6JO  bJD 

2 

3 

^t*'  rt  g 

3 
0 

O 
tj 

x  S 

"I 

V 

9 

a 

^>s 

OJ  l-i 

cc 

Locality. 

a 
o 

a 

00 

a 

Sg 

o  o 

ea  .,_, 
a  - 

" 

In 

•3 

fl 

rl  -s  - 

"3 

^ 

§ 

a 

G 

^ 

cd 

3 

"-"   3 

o 

tn  M 

O 

PH 

£ 

*j*2 

a 

jj 

0 

Q  . 

S 

g 

"a; 

o 

U 

_3 

li 

O"* 

o 

p 

a; 

"E 

c 

'S 

rt 

'o 

Standard  coke,Connellsv'le 
Walston 

12.46 
16.63 

20.25 
23-4 

47-47 
63-36 

77-15 
89.15 

61-53 
71.07 

38.47 
28.93 

284 
270 

114 
109 

i 

3-5 
3-7 

1500 
1900 

TABLE    3. — CHEMICAL   ANALYSES. 


Locality. 

Fixed 
Carb. 

Mois. 

Ash. 

Sulph. 

Phos. 

Volatile 
matter. 

Standard  coke,  Connells- 
ville   

87.46 

Walston  coke,  (A.  S.  Me 
Creath  72-hour  coke)....  

88.476 

.148 

9-731 

•951 

.008 

.692 

TABLE  4.  . 

Moisture 058 

Volatile  matter 634 

Fixed  carbon 89.960 

Sulphur 790 

Phosphorus 014 

Ash 8.554 


l6  METALLURGY    OF    CAST    IRON. 

Forty-eight-hour  and  72-hour  coke  refers  to  the  time 
the  coal  is  subjected  to  the  coking  process  in  the  oven. 
Table  i,  page  13,  shows  that  48 -hour  and  7 2 -hour  coke 
varies  in  the  length  of  time  it  is  in  an  oven,  and  that 
the  actual  time  coal  is  coked  is  largely  regulated  by 
local  conditions  best  suiting  the  working  convenience 
of  the  coke  workers  in  going  the  rounds  of  their  ovens ; 
and  we  might  say  we  have  instead  of  48 -hour  and 
7  2 -hour  coke,  two-  and  three-day  coke.  Where  ma- 
chinery is  used  instead  of  mules  and  hand  labor  in 
charging  ovens,  the  coal  is  insured  a  longer  coking 
than  forty-eight  and  seventy-two  hours,  as  by  the 
means  of  machinery  the  ovens  can  be  charged  earlier 
in  the  day  and  the  coking  resumed.  Seventy-two  hour 
coke,  which  is  used  chiefly  by  foundrymen,  is  gener- 
ally due  to  coke  remaining  in  the  ovens  over  Sunday, 
which  day  the  cokers  do  not  work.  Seventy-two 
hour  coke  is  not  always  up  to  the  high  standard  that 
many,  claim  for  it.  The  author  has  melted  with 
furnace,  or  48-hour  coke,  for  six  months  at  a  time, 
and  he  cannot  say  that  the  fact  of  its  being  48- 
hour  coke  caused  it  to  be  unsatisfactory,  when  the 
difference  in  price  was  considered.  Nevertheless, 
as  a  rule,  48-hour  coke  is  of  less  value  as  a 
melter  than  7  2 -hour  coke,  as  the  latter  is  generally  a 
harder,  larger,  and  cleaner  fuel.  As  large  a  coke  may 
be  produced  from  a  48 -hour  as  a  7  2 -hour  burning,  but 
owing  to  the  conditions  which  permit  furnacemen  to 
use  smaller  and  more  dusty  coke  with  less  evil  results 
than  are  apt  to  follow  its  use  in  cupola  work,  48 -hour 
coke  is  not  selected  nor  handled  with  the  same  care  as 
7  2 -hour  coke,  and  hence  the  former  will  give  a  greater 
yield  from  the  same  amount  of  coal.  The  method  used 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE.  1 7 

for  obtaining  the  best  "  selected  "  coke  is  that  of  cool- 
ing off  the  coke  inside  the  ovens  and  in  picking  out  the 
black  ends  and  fine  as  well  as  poorly  burned  coke. 
There  are  times  when  coke  is  burned  from  ninety-six 
to  one  hundred  and  twenty  hours,  and  then  again  only 
coked  twenty-four  hours  in  bee-hive  ovens ;  but  this 
latter  product  is  generally  not  suited  for  making  or 
melting  iron.  It  is  said  that  if  coke  makers  take  the 
precaution,  they  can  make  24-hour  coke  nearly  as  good 
as  the  48 -hour  article,  with  the  exception  of  its  not 
being  quite  as  long  in  its  body. 

Gas  house  coke  is  obtained  from  the  retorts  used  in 
gas  works  to  produce  illuminating  gas,  or  from  the 
retorts  used  in  manufacturing  coal-tar  or  other  by- 
products. Some  kinds  of  coal  will  produce  gas  coke 
by  the  use  of  which  iron  can  be  melted.  Coal  of  the 
quality  found  in  the  Connellsville  region  is  suitable 
for  making  this  coke.  When  gas,  or  soft  coke,  is  used 
for  melting  it  is  often  necessary  to  use  double  the  quan- 
tity or  number  of  bushels  than  of  hard  oven  coke,  and 
at  its  best  it  is  an  undesirable  fuel  for  this  purpose. 
It  will  often  give  good  satisfaction  in  drying  cores  or 
moulds,  and  work  even  better  than  hard  coke,  but 
much  more  of  it  must  generally  be  used  than  of  the 
oven,  or  hard  coke. 

Comparison  of  Connellsville  coke  with  others  has 
shown  that  the  opinion  held  by  many  that  Connells- 
ville coke  could  not  be  equalled,  was  an  error.  The 
localities  shown  in  Table  5,  by  Mr.  John  R.  Proctor, 
published  in  the  Kentucky  Geological  Survey  Report, 
are  furnishing  considerable  good  coke  to  furnacemen 
and  founders. 


i8 


METALLURGY    OF    CAST    IRON. 


TABLE    5. — ANALYSES    OF    COKE    FROM   DIFFERENT    LOCALITIES. 


Where  Made. 

Fixed 
carbon. 

Ash. 

Sulphur. 

Connellsville,  Pa.    (Average  of  3  samples.)  
Chattanooga,  Tenn.                    '4 
Birmingham,  Ala.                       '4                     .... 

88.96 
80.61 
87.29 

9-74 
16.34 
10.54 

0.810 
1-595 
I-I95 

Pocahontas,  Va.                 '          '   3        " 

92-53 

5-74 

0.597 

New  River,  W.  Va.            '          '   8        " 

92.38 

7.21 

0.562 

Big  Stone  Gap,  Ky.                     '7 

93-23 

5-69 

0.749 

Coke  of  a  silvery  metallic  lustre  and  possessing  a 
solid,  hard  body,  with  cells  well  connected  and  of  uni- 
form structure,  can  generally  be  called  ' '  good  coke. ' ' 
The  hidden  element  that  might  do  serious  harm  in 
such  coke  is  sulphur  or  phosphorus,  for  these  can  be 
high  or  low  in  any  grade  of  coke.  This  can  only  be 
properly  determined  by  analysis.  The  coke  generally 
condemned  by  the  consumer,  especially  the  founder, 
is  small  sized  coke,  mixed  with  ash  cinder  or  coke 
dust;  then  again  coke  that  is  dark  in  its  general 
appearance,  having  black  ends,  and  soft  in  quality. 
Even  when  the  coke  has  all  other  commendable  quali- 
ties but  is  in  small  pieces,  such  is  often  sufficient  to 
produce  bad  results  in  melting  iron.  Then  again  coke 
may  not  possess  the  much  desired  ' '  silvery  or  bright 
metallic  lustre  ' '  and  still  be  good,  if  it  is  only  large 
and  hard  in  character,  possessing  a  good  cellular 
structure.  The  harder  or  more  dense  the  coke,  the 
stronger  blast  is  required  in  melting  iron. 

Black  ends  are  of  two  kinds.  One  is  called  black 
tops  and  the  other  black  butts,  the  latter  coming  from 
the  bottom  of  the  charge  of  coal  as  it  lays  in  an  oven, 
and  the  former  from  the  top.  Black  tops  are  rarely 
injurious,  while  black  butts  can  be.  These  latter  may 
often  be  caused  by  reason  of  an  inch  or  more  of  the 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE.  19 

coal  lying  on  the  bottom  of  a  cold  or  hot  oven  being 
uncoked  or  fused.  The  coking  process  proceeds  from 
the  top  of  a  charge.  There  are  times  when  the  heat 
of  the  crown  of  a  very  hot  oven  may  fuse  the  top  sur- 
face of  the  coal  and  form  a  thin  crust  or  film  which  will 
prevent  the  usual  freedom  in  the  escape  of  gases. 
These  being  held  back  for  a  time,  will  deposit  a  soot 
or  lampblack  in  the  cells  of  the  forming  coke  so  as  to 
result  in  giving  black  tops,  or  a  black  coke.  As  soon 
as  the  gases  gain  sufficient  pressure  to  burst  through 
the  top  crust  or  film,  then  the  deposit  of  sooty  matter 
ceases. 

Stock  coke  is  generally  of  a  smaller  size  than  that 
conveyed  directly  from  ovens  to  cars  for  shipment, 
for  the  reason  that  it  is  broken  up  by  extra  handling. 
It  is  called  stock  coke  for  the  reason  that  it  is  coke 
that,  for  want  of  orders  or  cars  to  make  shipment,  has 
to  be  stored  in  large  piles  at  the  coke  works  —  some- 
times months  and  sometimes  years.  Lying  thus  it  is 
subjected  to  rain,  snow,  dust,  and  smoke,  collects 
excessive  moisture,  and  becomes  dirty.  Sometimes, 
in  order  to  keep  the  ovens  going  and  save  stocking, 
heavy  charges  are  resorted  to  and  the  coal  coked  from 
ninety-six  to  one  hundred  and  twenty  hours.  This 
process  causes  a  loss  of  coke  in  the  ovens. 

The  fixed  carbon  in  coke  used  for  furnace  and  foun- 
dry work  generally  ranges  from  eighty  to  ninety  per 
cent.  Sometimes  it  is  considerably  under  this,  and 
occasionally  it  may  exceed  the  highest  limits  by  two 
to  five  per  cent.  Some  of  the  carbon  is  lost  by  the 
process  of  coking.  If  cooled  by  water  at  the  proper 
time  the  percentage  lost  is  rarely  very  large.  When 
more  than  from  two  to  four  per  cent  of  carbon  is  lost, 


20  METALLURGY    OF    CAST    IRON. 

either  the  coal  is  inferior  to  Connellsville  coal  or  it  has 
not  been  treated  properly,  and  the  coke  has  been 
allowed  to  waste.  The  amount  of  loss  is  due  to  sev- 
eral factors.  One  may  be  the  indisposition  of  the  coal 
to  coke,  and  again  it  may  be  the  fault  of  the  ovens  and 
their  treatment. 

The  ash  in  coke  is  an  impurity  which,  like  phos- 
phorus and  sulphur,  lessens  the  commercial  value  of 
the  coke  as  the  percentages  increase.  The  ash  in  fur- 
nace and  foundry  coke  generally  ranges  from  nine  to 
fourteen  per  cent.  It  may  exceed  this  two  to  four  per 
cent,  or  be  as  low  as  five  per  cent.  The  ash  of  coke 
generally  includes  the  impurities  found  in  Table  6, 
obtained  by  Mr.  E.  C.  Pechin.  The  less  ash  coke 
contains  the  greater  is  its  value,  generally  speaking, 
although  very  low  ash  is  not  desirable  in  all  cases.  It 
is  often  beneficial  in  assisting  the  formation  of  a  good 
slag.  The  coke  made  from  washed  coal  contains  less 
ash  and  sulphur  than  that  made  from  unwashed  coal. 

TABLE   6. — ANALYSES   OF   ASH   IN   CONNELLSVILLE   COKE. 

Silica 5.413 

Alumina 3.262 

Sesquioxide  of  iron 0.479 

Lime 0.243 

Magnesia 0.007 

Phosphoric  acid 0.012 

Potash  and  soda Traces. 


9.416 

The  chemical  properties  desirable  in  coke  are,  first, 
low  sulphur  and  often  low  phosphorus,  and  second, 
high  carbon.  As  a  rule  when  adopting  a  new  brand 
of  coke,  and  often  in  the  use  of  old  ones,  it  will  pay  a 
founder  to  assure  himself  as  to  the  chemical  properties 
of  the  coke  before  using  it.  This  is  a  practice  which 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE. 


21 


furnacemen    generally  follow.     In  sampling  coke  for 
analysis  much  more  should  be  selected  than  is  actually 


o  £ 

i! 


38 

u 


required,  and  the  sample  obtained  should  be  carefully 
picked  from  different  parts  of  a  pile  or  car. 

High  sulphur  in  coke  may  lead  to  very  serious  results 


22  METALLURGY    OF    CAST    IRON. 

in  founding  as  well  as  in  furnace  work.  It  is  generally 
very  essential  in  making  coke  that  plenty  of  pure  water 
be  had.  A  drought  can  make  water  so  scarce  as  to 
compel  the  use  of  mine  water.  Such  usually  contains 
enough  sulphur  to  seriously  affect  the  coke  when 
quenching  the  fire.  The  process  of  coking  has  much 
to  do  in  controlling  the  amount  of  sulphur  in  coke. 
Coke  from  the  same  mine  and  oven  can  and  often  does 
vary  greatly  in  the  percentage  of  sulphur.  If  sulphur 
is  above  .90  per  cent  it  can  often  be  told  by  the  odor  of 
escaping  gases  and  the  stifling  fumes  a  furnace  or 
cupola  will  emit,  as  compared  with  coke  below  .80 
per  cent.  High  sulphur  can  often  be  detected  by 
the  eye,  due  to  its  causing  yellow  spots  or  stains  to 
appear  on  the  surface  of  the  coke.  A  quick  test  is 
made  by  heating  pieces  red-hot  and  dropping  them 
into  a  pail  of  water.  This  drives  off  the  sulphur  to 
such  a  degree  that,  with  a  little  practice,  one  can  detect 
differences  in  the  amount  of  sulphur  coke  may  hold. 
The  best  way,  of  course,  to  determine  the  sulphur  or 
other  properties,  is  by  chemical  analysis. 

Phosphorus  in  coke  may  be  injurious  and  then  again 
beneficial  to  both  furnacemen  and  founders.  This 
depends  upon  the  percentage  of  phosphorus  desired  in 
any  special  brand  or  mixture  of  iron,  as  whatever  phos- 
phorus coke  contains  is  generally  taken  up  by  the  iron 
when  being  made  or  remelted.  If,  for  example,  regu- 
lar Bessemer  iron  or  castings  calling  for  phosphorus 
not  exceeding  .10  is  desired,  the  high  phosphorus  coke 
would  certainly  be  injurious ;  but  if  it  is  foundry  iron 
that  is  desired  to  make  thin  castings,  then*  higher 
phosphorus  coke  is  essential,  as  increasing  phosphorus 
increases  fluidity,  see  page  216.  It  always  requires 


THE    MANUFACTURE    AND    PROPERTIES    OF    COKE.          23 

chemical  analysis  to  detect  the  phosphorus  while  the 
eye  may  at  times  detect  the  sulphur. 

The  best  brand  or  grade  of  coke  to  use  in  smelting 
or  melting  iron  is  often  regulated  by  its  cost.  Certain 
localities  in  the  Connellsville  region  are  generally 
conceded  to  give  the  best  grades  of  coke  to  be  found 
in  this  country,  but  the  great  distance  of  many  con- 
sumers from  this  point  makes  the  cost  so  great  that 
they  use  other  brands.  However,  almost  every  locality 
can  furnish  different  grades,  and  it  is  often  surprising 
how  much  less  of  the  best  grade  is  required  than  of 
poorer  ones  in  doing  the  same  work  in  melting.  It  is 
rare  that  there  is  any  economy  in  using  poor  grades 
of  coke  if  the  difference  in  price  is  at  all  reasonable. 

In  the  first  use  of  coke  in  cupolas  it  was  bought  and 
charged  by  the  bushel,  instead  of  by  weight  as  at 
present.  Coke  weighs  from  thirty  to  seventy  pounds 
per  bushel,  the  more  dense  and  hard,  the  heavier  it  is. 
In  using  coke  in  cupolas  it  is  very  important  to  note 
its  hardness  and  be  governed  by  the  same,  as  with  the 
same  weight  of  coke  in  good  soft  and  hard  grades  one 
can  readily  conceive  that  the  bed  and  charges  of  coke 
would  vary  in  height  and  could  often  cause  trouble,  as 
for  example  the  same  weight  in  a  soft  coke  that  would 
bring  it  up  to  eighteen  inches  or  so  above  the  top  of 
the  tuyeres,  could,  in  hard  coke,  bring  it  only  to  a 
level  of  the  tuyeres  or  a  little  above,  which  all  experi- 
enced founders  know  would  soon  bung  up  or  prevent 
a  cupola  from  melting.  Where  one  is  called  upon  to 
use  a  soft  coke  —  and  which  will  not  permit  cupolas 
to  run  as  clean  or  as  long  as  hard  coke,  although  soft 
coke  may  give  good  hot  iron — -he  should,  as  a  rule,  use 
less  weight  of  the  soft  coke  than  of  the  hard  in  the  bed 


24  METALLURGY    OF    CAST    IRON. 

and  between  charges,  and  at  the  same  time  reduce  the 
weight  of  the  iron  in  both  the  bed  and  charges,  as,  if  the 
same  weight  of  soft  as  of  hard  coke  found  best  is  used, 
the  bed  of  fuel  would  be  raised  above  that  point  best 
for  rapid  and  economical  melting.  It  is  to  be  under- 
stood that  this  does  not  mean  that  a  less  weight  of  soft 
coke  will  be  required  throughout  the  whole  heat.  Re- 
ducing the  weight  of  iron  on  the  bed  of  coke  and 
between  the  charges  calls  for  a  greater  number  of 
charges  of  coke,  as  well  as  of  iron,  and  thus  may  cause 
as  much  or  a  greater  weight  of  soft  coke  to  run  off  a 
heat  than  if  hard  coke  had  been  used.  When  using 
soft  grades  of  coke  and  following  the  above  sugges- 
tions, the  rule  of  charging  three  pounds  of  iron  to  one 
of  coke  on  the  bed  and  ten  to  one  between  the  charges 
will  often  serve  as  a  guide  in  decreasing  the  weight  of 
iron  to  approximately  correspond  with  the  decrease  in 
the  weight  of  fuel  that  may  be  found  best  to  adopt. 
This  is  assuming  the  height  of  tuyeres  to  be  about 
eighteen  inches  above  the  bottom  plate;  with  lower 
tuyeres  three  to  five  pounds  of  iron  to  one  pound  of 
coke  may  often  be  charged  on  a  bed  of  coke.  Where, 
by  reason  of  coke  being  soft,  dull  iron  is  obtained,  or 
the  cupola  bungs  up  badly,  such  trouble  may  not  only 
be  decreased  by  making  smaller  charges  of  iron,  but  a 
milder  blast  is  also  generally  desirable.  A  strong  blast 
often  blows  all  the  life  out  of  soft  coke,  facing  the 
tuyeres,  and  often  leaves  a  space  that  can  fill  up  with 
chilled  slag  or  iron  droppings  which  can  soon  bung  up 
or  stop  a  cupola  from  melting.  For  further  informa- 
tion on  charging,  etc.,  of  cupolas,  see  American  "  Foun- 
dry Practice  "  and  ''Moulder's  Text  Book." 


CHAPTER  II. 

PROPERTIES  OF  ORES    USED  IN  MAKING 
CAST  IRON. 

A  brief  description  of  elements  in  ores  will  point  out 
varying  qualities  in  the  material  from  which  cast  iron 
is  made,  and  also  help  impress  one  with  the  great 
difference  ores  can  and  do  make  in  the  different 
brands  of  iron.  The  ores  from  which  cast  iron  is 
made  are  largely  oxides  of  iron,  containing  other  ele- 
ments and  impurities,  among  which  generally  exist 
more  or  less  manganese,  sulphur,  phosphorus,  alumina, 
and  silica.  It  is  called  '  *  rich  ore  ' '  when  high  in  iron, 
and  ' '  lean  ore, ' '  when  low.  The  oxides  of  iron  are 
known  as  '  *  ferric  oxide  ' '  and  *  *  ferrous  oxide. ' '  The 
former,  theoretically,  contains  70  per  cent  of  iron  and 
30  per  cent  of  oxygen,  the  latter  77.78  per  cent  of  iron 
and  22.22  per  cent  oxygen.  Percentages  of  iron  and 
oxygen  vary  in  the  ores,  but  the  above  percentages 
constitute  distinct  chemical  compositions. 

Many  soils  and  rocks  contain  more  or  less  oxide 
of  iron,  but  such  material  is  not  generally  considered 
suitable  to  make  cast  iron  unless  it  contains  more  than 
30  per  cent  of  iron.  Ores  are  now  very  rarely  used  for 
making  cast  iron  or  pig  metal  unless  they  contain  more 
than  40  per  cent  of  iron.  The  ore  used  in  the  manu- 


26  METALLURGY    OF    CAST    IRON. 

facture  of  cast  iron  and  worked  to  an  economical  advan- 
tage generally  contains  from  50  to  65  per  cent  of  iron, 
and  it  is  rare  that  ore  of  sufficient  quantity  to  keep  a 
furnace  going  steadily  on  a  fair  uniform  product  can 
be  obtained  containing  more  than  70  per  cent  of 
iron. 

The  pig  iron  which  the  founder  uses  (barring  ferro- 
silicon,  etc.)  generally  contains  from  92  to  96  per  cent 
of  metallic  iron,  with  4  to  8  per  cent  of  impurities, 
chiefly  carbon,  silicon,  manganese,  sulphur,  and  phos- 
phorus. These  impurities,  while  called  such,  are  really 
the  elements  which  make  iron  of  any  practical  value 
in  the  various  industries.  According  to  changes  in 
the  proportions  of  these  so-called  impurities,  we  are 
given  the  different  grades  of  pig  iron  so  essential  to 
meet  varying  conditions  called  for  in  our  widely  diver- 
sified use  of  iron. 

Silica  ranges  in  ores  from  a  trace  to  20  per  cent, 
and  often  higher.  The  ores  generally  used  for  ordi- 
nary pig  metals  contain  from  3  to  8  per  cent  of  silica. 
Next  to  the  iron  in  the  ore.  silica  is  the  largest  consti- 
tuent in  nearly  all  ores  used.  The  combined  silica  in 
the  ores,  fuel,  and  flux  gives  the  silicon  to  the  iron. 
Where  high  or  ferro-silicon  iron  is  desired,  high  silicious 
ores  are  used  in  connection  with  a  greater  amount  of 
fuel  and  higher  temperature  in  the  furnace.  With 
like  fuels,  ores,  and  fluxes  the  higher  the  temperature 
in  a  furnace,  the  higher  silicon  will  be  found  in  the 
iron.  The  higher  the  temperature  desired,  the  more 
fuel  it  is  necessary  to  use.  Furnaces  may  work  so  cold 
by  reduction-  of  fuel,  or  bad  working,  as  to  cause  the 
greater  part  of  the  silica  to  be  carried  off  with  the  slag, 
instead  of  its  making  silicon  in  the  iron. 


PROPERTIES    OF    ORES    USED    IN    MAKING    CAST    IRON.      27 

Manganese   is   found   in   nearly  all   iron   ores.     It 

readily  alloys  with  iron,  and  all  the  manganese  con- 
tained in  pig  iron  is  obtained  from  the  ores.  Manga- 
nese occurs  in  ores  in  the  form  of  manganese  dioxide 
and  manganese  oxide.  Some  ores  are  so  high  in 
manganese  that  they  are  called  manganiferous  ores, 
and  of  late  years  their  reduction  has  been  achieved  in 
blast  furnaces  about  as  readily  as  iron  ore  is  reduced, 
although  at .  one  time  it  was  thought  impossible  to 
obtain  high  manganese  pig  from  a  blast  furnace. 

Ferro=manganese  is  obtained  by  smelting  mangan- 
iferous ores  in  a  blast  furnace,  and  is  placed  on  the 
market  as  a  commercial  product  containing  from  40 
per  cent  to  90  per  cent  of  manganese.  The  standard 
contains  from  79  to  8 1  per  cent. 

Spiegeleisen  or  "  Spiegel "  is  a  product  of  manganif- 
erous ores,  but  lower  in  manganese  than  ferro-manga- 
nese.  It  ranges  from  7  per  cent  to  40  per  cent  of 
metallic  manganese. ,  The  standard  contains  from  19 
to  21  per  cent.  In  this  form  it  generally  presents  a 
silvery  white  fracture  with  a  crystalline  structure.  By 
some  this  metal  is  called  "looking-glass  iron,"  the 
English  translation  of  Spiegeleisen.  Spiegeleisen  is 
readily  produced,  whenever  sufficient  manganese  is 
present  in  the  ore.  Both  these  manganese  metals  are 
chiefly  used  in  the  manufacture  of  steel  in  its  many 
and  various  grades. 

Phosphorus  exists  in  most  iron  ores.  Almost  all  the 
phosphorus  contained  in  the  ore,  fuel  and  flux  is 
reduced  and  absorbed  by  the  metallic  iron  when 
smelting  or  remelting  it.  Low  phosphorus  ores  are 
generally  of  greater  value  than  high  phosphorus  ores. 
For  Bessemer  iron,  in  which  phosphorus  must  not 


28 


METALLURGY    OF    CAST    IRON. 


exceed  .10,  lower  phosphorus  ores  must  be  used  than 
in  making  foundry  irons.  It  is  often  found  beneficial 
to  have  pig  iron  contain  as  high  as  1.50  phosphorus, 
owing  to  the  fact  that  phosphorus  possesses  the  quality 
of  giving  life  and  fluidity  to  molten  metal,  which  is 
most  desirable  in  running  thin  castings. 

For  de-phosphorizing  magnetic  ores,  different  kinds 
of  devices  have 
been  used.  Fig.  5 
will  convey  an  idea 
of  the  principles 
involved  in  the 
separation  of  "tail- 
ings ' '  and  ' '  con- 
centrates ' '  by  the 
employment  of 
magnetic  power. 
By  the  use  of  sepa- 
rators or  magnets 
from  50  per  cent 
to  80  per  cent  of 
the  phosphorus 
originally  c  o  n  - 
tained  in  ore  is 
ores  which  contain  pyrites  (which  is  a  combination 
°f  53-3  Per  cent  of  sulphur  with  46.7  per  cent  of  iron) 
can  have,  it  is  also  said,  a  larger  per  cent  of  their 
sulphur  contents  removed  by  magnetic  concentra- 
tion with  a  separator  than  by  roasting,  as  referred  to 
below.  Sometimes  the  sulphur  is  present  in  pyrrho- 
tite  (which  is  39.5  per  cent  of  sulphur  combined  with 
60.5  per  cent  of  iron)  in  which  state  experiments  have 
shown  that  there  would  be  as  much  sulphur  in  the  con- 


no.    5. — BUCHANAN   SEPARATOR. 

said    to    be    removed.     Magnetic 


PROPERTIES  OF  ORES  USED  IN  MAKING  CAST  IRON.    29 

centrates  as  existed  in  the  crude  ores,  and  hence,  sepa- 
rators to  eliminate  sulphur  from  this  class  of  ore  have 
proved  a  failure. 

High  sulphur  ores  are  sometimes  subjected  to  a 
process  called  "roasting""  or  "calcination"  which 
generally  drives  off  a  greater  part  of  the  sulphur. 

Varieties  of  iron  ores  are  very  numerous.  In  order 
to  classify  them  they  are  chiefly  placed  under  one  or 
the  other  of  the  following  heads:  hematites,  magne- 
tites, and  carbonates.  Of  the  first  there  are  two  kinds, 
known  as  the  brown  and  red  hematites.  There  is 
more  red  hematite  used  than  all  the  other  ores  com- 
bined. Red  hematite  is  generally  quite  free  from 
sulphur,  and  it  is  found  in  almost  every  shape  in  which 
ore  is  found  and  exists  in  large  quantities.  Messaba 
ore,  a  soft  ore  now  largely  used  to  make  both  Besse- 
mer and  foundry  iron,  is  a  red  hematite  which,  it  was 
thought,  a  few  years  ago,  by  experts,  to  be  unsuited 
for  the  blast  furnace  on  account  of  its  being  such  a 
dusty,  fine  soil  material. 

Magnetic  ore  is  the  next  variety  generally  recognized 
in  the  order  of  classification.  This  ore  is  found  in 
veins  and  is  generally  classed  with  the  hard  and 
refractory  ores.  It  is  generally  a  dense  black  material, 
which  must  be  crushed  or  broken  to  suit  the  varying 
conditions  of  smelting.  In  Canada  and  New  Zealand 
magnetic  ore  is  found  in  the  form  of  coarse  gravel  or 
sand,  which,  as  a  rule,  furnacemen  prefer  not  to  use  if 
it  can  be  avoided.  Magnetic  ores  are  often  discovered 
by  the  attraction  they  exert  upon  the  compass  needle. 
They  are  often  very  free  of  phosphorus  and  sulphur, 
but  if  they  are  too  high  in  phosphorus  and  sulphur 
they  will  not  be  used  as  long  as  sufficient  ore  of  suit- 


30  METALLURGY    OF    CAST    IRON. 

able  grade  can  be  obtained  without  the  cost  necessary 
to  prepare  objectionably  high  sulphur  and  phosphorus 
ore  for  smelting. 

Brown  hematites  include  bog  ores,  which  are  found 
in  shallow  rivers,  etc. ,  and  are  now  very  little  used ; 
they  are  largely  the  result  of  the  oxidation  of  the 
carbonates  of  iron.  No  ore  is  more  irregular  in  its 
characteristic  qualities.  It  may  be  of  a  yellow  as  well 
as  a  brown  color.  It  is  generally  porous  and  easy  to 
reduce  and  smelt  in  a  blast  furnace.  It  is  found  mixed 
in  undue  proportion  with  earthy  and  gangue  matter 
and  often  rich  in  carbonate  of  lime,  and  is  also  gener- 
ally high  in  phosphorus.  It  is  found  in  beds  and 
veins  and  often  forms  the  cover  of  copper  ores. 

Carbonate  and  spathic  ores  are  generally  of  a  whitish 
color,  but  they  are  often  found  mixed  with  manganese, 
which  turns  them  brown.  They  are  largely  found  in 
massive  veins  of  great  thickness  and  in  combination 
with  other  carbonates  and  may  be  of  a  greenish  gray 
color.  Brown  hematites  are  also  found  existing  in 
sands  or  soils  of  a  coarse  character.  There  is  some 
dispute  as  to  their  value.  Some  claim  that  they  excel 
red  hematites  for  making  high  grade  iron.  A  variety 
of  carbonate  of  iron  ores  is  known  as  clay  iron  stone 
by  reason  of  its  being  found  in  the  clay  bands  of  the 
coal  fields.  This  class  of  ore  is  largely  used  in  Scot- 
land as  well  as  in  England.  ' '  Black  band  ' '  is  one 
variety  of  this  class  of  ores,  and  is  of  a  glossy  black 
color. 

Black  band  ores  give  strong  irons,  and  when  mixed 
with  soft  hematite  ores  make  a  soft,  or  good  grade  of 
Scotch  iron ;  but  of  late  years  they  have  become  so 
scarce  that  they  cannot  compete  with  the  more  plen- 


PROPERTIES    OF    ORES    USED    IN    MAKING    CAST    IRON.      31 

tiful  ores,  which  can  be  made  to  produce  an  iron  that 
will  be  accepted  in  some  cases  as  equally  satisfactory. 
An  ore  approaching  black  band,  and  called  '  *  band  iron 
stone, ' '  is  now  often  used.  This  is  of  a  bluish  gray 
color,  and  exists  in  coal  formations  similar  to  black 
bands.  Some  of  these  ores  are  smelted  in  their  raw 
state,  while  others  are  roasted  and  converted  into 
higher  oxides  before  being  smelted. 

Titaniferous  ores,  free  of  sulphur  and  phosphorus, 
containing  10  to  16  per  cent  of  titanium  and  50  to  60 
per  cent  iron,  found  in  the  Adirondack  mountains,  are 
now  being  used  to  make  ferro -titanium  by  the  Ferro- 
Titanium  Co.,  Niagara  Falls,  N.  Y.,  Mr.  A.  J.  Rossi 
being  the  inventor  of  the  process.  Nearly  half  the 
ores  found  on  this  continent  contain  more  or  less 
titanium,  but  furnacemen  have  always  found  it  most 
difficult  to  use  titaniferous  ores  on  account  of  the 
titanic  acid  making  an  infusible  slag.  Since  Mr.  Rossi 
has  lately  succeeded  (January,  1901)  in  overcoming  this 
difficulty,  it  is  rather  early  to  predict  to  what  extent 
this  ferro-titanium  may  prove  of  value  to  steel  manu- 
facturers and  founders,  as  titanium  is  known  to 
strengthen  or  chill  iron  by  holding  the  carbon  more  in 
a  combined  form,  similar  as  with  manganese  ario 
sulphur. 

Mill  cinder  iron  is  a  grade  of  metal  derived  from  the 
smelting  of  rolling  mill  cinder  exclusively,  or  in  admix- 
ture with  iron  ores.  Rolling  mill  cinder  can  be  classed 
under  the  heads  of  puddle,  tap  cinder,  heating  furnace, 
flue  cinder,  roll  cinder,  and  bosh  cinder;  the  latter 
being  collected  in  a  trough  or  bosh  of  water  in  which 
the  puddlers  cool  their  tools.  Roll  scale  is  generally 
supposed  to  contain  the  most  iron,  followed  in  order 


32  METALLURGY    OF    CAST    IRON. 

by  bosh,  tap,  and  flue  cinder.  Mill  cinder  is  generally 
used  first  because  it  can  often  be  purchased  for  about 
one-half  the  price  of  iron  ore  and  because  it  often  con- 
tains a  large  percentage  of  iron. 

Tap  cinder  is  of  two  varieties,  one  is  "boilings" 
that  flow  over  the  floor  plate  of  a  puddling  furnace 
when  making  the  iron,  and  the  other  is  '  *  tappings 
that  runs  out  of  a  furnace  at  the  end  of  the  heat.  As 
a  general  thing  boilings  are  very  much  higher  in  phos- 
phorus and  silica  than  tappings.  Mill  cinder,  as  above 
outlined,  is  composed  largely  of  protoxide  of  iron  and 
silica.  It  contains,  at  times,  ferric  and  magnetic 
oxides  and  is  generally  high  in  phosphorus.  Table  9 
is  an  analysis  of  four  samples  of  mill  cinder  which  the 
author  secured  to  give  an  idea  of  the  chemical  compo- 
sition of  the  same.  As  it  would  take  about  two  tons 
of  such  cinder  to  make  one  ton  of  iron,  there  would  be 
about  twice  the  amount  of  phosphorus  in  the  iron 
produced  than  is  contained  in  the  cinder  ore  where  all 
cinder  was  used. 

TABLE   9. — ANALYSIS    OF   MILL    CINDER. 


A 

i. 

2. 

3- 

4- 

*r 
Iron       

52.48 

52.20 

52-91 

53.70 

Phosphorus     

•34 

•47 

•37 

Silica                       

24.65 

25.06 

23.43 

23.39 

Manganese  

•34 

•45 

•57 

•35 

Iron  mill  cinder  is  only  used  for  making  foundry  or 
nill  iron.  It  is  not  used  for  making  Bessemer  for  the 
reason  that  it  would  raise  the  phosphorus  too  high, 
which  for  foundry  iron  is  not  so  objectionable ;  in  fact, 
foundry  iron  often  requires  high  phosphorus.  It  can 
be  said  that  a  few  are  now  using  steel  cinder  in  making 


PROPERTIES    OF    ORES    USED    IN    MAKING    CAST    IRON.      33 

Bessemer  iron,  owing  to  such  being  very  low  in  phos- 
phorus. Aside  from  the  iron  being  low  (see  Chapter 
XXXIV.),  it  is  mainly  the  phosphorus  that  is  to  be 
feared  in  mill  cinder  iron,  as  this  cannot  well  be  elim- 
inated. If  the  "  iron  "  is  lower  and  the  phosphorus 
higher  than  is  beneficial  in  pig  metal  there  are  grounds 
for  rejecting  it,  but  otherwise  the  foundryman  is  rarely 
justified  in  condemning  mill  cind'er  mixed  pig  iron  on 
the  ground  that  it  contains  slag  because  cinder  was 
used  in  making  the  iron,  until  he  has  tested  it  to  have 
a  knowledge  of  its  chemical  constituents  and  physical 
properties.  Founders  have  used  mill  cinder  mixed 
pig  iron  when  they  thought  there  had  not  been  an 
ounce  of  cinder  mixed  with  the  ore.  Not  only  is  mill 
cinder  mixed  with  ores,  but  a  furnace  has  been  kept 
going  steadily  making  pig  metal  with  simply  all  mill 
cinder.  Mr.  C.  I.  Rader  has  done  this  at  the  Sheridan 
Furnace,  Sheridan,  Pa.,  in  making  forge  or  mill  iron. 


CHAPTER  III. 

CONSTRUCTION  OF  BLAST  FURNACES. 

In  the  first  days  of  furnace  practice  the  necessity  for 
good  deep  foundations  was  not  realized  as  at  the  pres- 
ent day.  If  deep  excavations  were  now  to  be  made 
tinder  many  of  the  old  furnaces  tons  of  iron  might  be 
found.  Past  experience,  dearly  bought,  has  taught 
the  furnaceman  to  provide  reliable  foundations.  In 
some  localities  the  depth  required  is  greater  than  in 
others,  and  in  some  cases  piles  have  to  be  driven 
before  the  foundation  is  started.  In  the  furnace 
shown,  Fig.  6,  the  stone-work  illustrated  is  about  five 
feet  deep,  on  top  of  which  a  bed  of  fire-brick  about 
five  feet  deep  is  laid  before  the  bottom  or  bed  of  the 
furnace  is  reached.  Such  foundations  are  costly,  but 
it  has  been  found  wiser  to  have  capital  lying  idle  in 
them  than  in  lost  iron. 

Generally  no  boiler  casing  is  now  used  to  support 
that  portion  of  the  hearth  and  bosh  which  incloses  the 
tuyeres  and  water  coolers  V.  This  portion  of  the 
furnace  has  its  fire-brick  work  supported  by  means  of 
wrought  iron  bands,  six  inches  wide  by  one  inch  thick, 
which  encircle  this  portion  at  the  height  of  every  two 
feet,  as  seen  at  S.  One  idea  of  not  encasing  this  part 
with  solid  boiler  plates  riveted  together,  as  is  done 
with  the  upper  part  of  the  furnace  as  shown,  is  so  as  to 
make  the  placing  and  attachment  of  coolers  convenient 


CONSTRUCTION    OF    BLAST    FURNACES. 


35 


and  permit  this  portion  of  the  furnace  brick-work  to  be 
exposed   to   the  cooling   influence  of  the  atmosphere 

as  much  as  possible. 
It  is  at  this  part  of 
the  bosh  and  hearth 
that  the  lining  is 
subjected  to  the 
greatest  heat.  Fur- 
naces are  contracted 
at  the  hearth  — 
which  constitutes 
all  that  portion  be- 
low the  tuyere  at  B, 
mainly  to  aid  the 
blast  in  reaching 
the  center  more 
strongly  and  caus- 
ing a  more  even 
distribution  of  its 
pressure  through- 

nr  Tm fl*  l\   out  the  fuel,  as  well 

.1       **  to  save  the  lin- 

ing.  Such  a  form 
not  only  assists  the 
blast  to  reach  the 
center,  but  the 
" batter"  or  bevel  of 
such  a  bosh  as  shown 
assists  in  supporting 
the  weight  of  stock 
charged,  thus  lessening  pressure  at  the  tap  hole,  per- 
mitting the  metal  to  be  under  better  control,  with  less 
liability  to  cut  the  breast  as  the  metal  flows  out  to  the 


FIG.    6. 


36  METALLURGY    OF    CAST    IRON. 

runner.  When  a  furnace  of  the  size  shown  is  full  of 
stock  (coke,  ore,  and  lime)  the  weight  bearing  down  on 
the  hearth  (when  a  furnace  is  working  properly)  is 
about  100  tons  of  coke,  160  tons  of  ore,  and  35  tons  of 
lime,  a  total  of  about  300  tons.  Such  a  weight  must 
be  very  effective  in  crushing  the  stock  in  the  reduced 
body  of  the  bosh,  so  as  to  greatly  retard  the  penetra- 
tion of  blast,  and  is  one  reason  for  the  high  pressure 
found  necessary  in  furnace  practice.  This  also  shows 
the  necessity  for  good  foundations. 

Decreasing  the  diameter  of  the  stack  from  its  larger 
portion  joining  the  bosh  up  to  the  top,  as  shown  in 
Fig.  10,  is  mainly  to  assist  in  preventing  the  stock 
from  "scaffolding,"  which  means  "hanging  up." 
(See  page  55.)  There  is  no  end  to  the  different  angles, 
etc. ,  given  to  furnaces,  each  style  having  its  advocates. 
We  now  have  Hawden  and  Howson  of  Middlesbrough, 
England,  who  are  using  a  plan  of  turning  present 
forms  upside  down.  We  might  also  mention  that 
strictly  straight  furnaces  have  been  tried,  but  these, 
it  is  said,  have  proved  a  failure,  as  a  study  of  these 
pages  would  lead  us  to  believe.  There  are  over  five 
hundred  blast  furnaces  in  the  United  States  today  and 
many  of  them  differ  more  or  less  in  their  * '  lines, ' ' 
etc.  The  shape  or  "  lines  "  now  generally  adopted  in 
this  country  for  coke  furnaces  are  more  in  accordance 
with  those  shown  in  Fig.  10,  in  which  the  hearth  is 
about  half  the  diameter  of  the  largest  part  of  the  bosh, 
and  the  throat  or  top  of  the  stack  about  two-thirds  of 
the  bosh's  largest  diameter,  in  a  height  of  about  eighty 
feet. 

The  construction  and  principle  of  furnace  tuyeres  is 
shown  at  B,  Fig.  6.  For  the  size  of  furnace  shown, 


CONSTRUCTION    OF    BLAST    FURNACES.  37 

eight  tuyeres  are  evenly  divided  around  the  circumfer- 
ence and  project  from  6  to  10  inches  beyond  the  lining. 
These  are  for  the  purpose  of  aiding  the  blast  to  reach 
the  center,  and  also  protecting  the  lining.  A  tuyere 
protruding  no  farther  than  the  face  of  the  lining  would 
rapidly  cut  out  the  brick-work  at  that  point.  These 
furnace  tuyeres  are  made  of  an  alloy  chiefly  composed 
of  copper,  so  as  to  approach  a  bronze  metal.  This 
class  of  metal  has  been  found  good  to  prevent  the 
melted  iron,  as  it  drops  down,  from  adhering  to  or 
clogging  around  the  tuyeres,  which,  if  it  should  occur, 
would  be  very  troublesome  and  liable  to  cause  much 
damage. 

To  prevent  these  tuyeres  from  melting  or  burning 
away  from  exposure  to  the  heat  of  the  fuel  and  hot 
blast,  a  constant  stream  of  cold  water  flows  through 
them,  going  in  at  H  and  coming  out  at  P.  Often 
through  irregular  workings,  tuyeres  may  become 
bunged  up  as  in  cupola  practice,  and  the  method  gen- 
erally followed  to  open  them  is  to  shut  off  the  blast  and 
endeavor  to  knock  a  hole  through  the  chilled  material, 
after  which  the  hot  blast  (of  about  1,000  degrees  heat) 
with  its  high  pressure,  which  ranges  from  6  to  24 
pounds,  instead  of  6  to  20  ounces,  as  in  cupola  practice, 
will  assist  to  cut  or  burn  away  the  chilled  material 
fronting  the  tuyeres.  Should  this  fail,  the  blast  is 
shut  off  and  the  tuyeres  are  pulled  out,  thereby  leav- 
ing a  big  hole  to  work  through,  and  by  means  of 
sledges  and  steel  bars  an  opening  is  cut  into  the  fur- 
nace and  the  cold,  chilled  debris  pulled  backward  out 
of  it.  In  replacing  such  a  tuyere,  a  large  lump  of  clay 
is  pushed  forward  into  the  face  of  the  hole  to  prevent 
the  heat  melting  the  tuyere,  and  then  the  tuyere  is 


38  METALLURGY    OF    CAST    IRON. 

pressed  or  knocked  inward  against  the  pressure  of  the 
stock  in  the  furnace  until  it  is  in  its  right  place.  After 
this  is  done,  any  clay  that  might  block  up  the  hole  in 
the  tuyere  to  prevent  blast  to  the  furnace  is  broken 
away  by  means  of  a  bar,  and  after  the  water  pipes  are 
attached,  the  blast  is  again  put  on.  The  removal  or 
insertion  of  furnace  tuyeres  is  an  operation  very  read- 
ily performed,  owing  to  the  taper  seen  in  the  stationary 
sleeve  at  T,  Fig.  6.  This  stationary  tuyere  support  is 
cast  hollow,  of  the  same  metal  as  the  tuyere  proper, 
and  is  kept  cool  by  a  flow  of  water  going  in  at  W  and 
coming  out  at  F.  It  is  very  rare  that  one  of  these 
sleeves  has  to  be  removed,  as  they  do  not  project  into 
the  furnace,  as  is  the  case  with  the  tuyere  proper. 

Coolers  are  very  important  in  furnace  construction 
to  provide  means  to  assist  in  lengthening  the  life  of  a 
lining.  Some  furnaces  are  better  provided  with  cool- 
ing appliances  than  others.  In  the  furnace  shown, 
water  is  admitted  to  a  suspended  cast-iron  receiver  (as 
seen  at  X),  which  encircles  the  furnace,  excepting  an 
opening  of  about  two  feet  at  the  front  or  breast  side  of 
the  furnace.  The  cold  water  is  admitted  to  this 
receiver  in  its  lower  division  at  M,  and  after  having 
done  its  work  it  flows  into  the  upper  division  and  is 
carried  off  through  the  waste  pipe  N.  The  pipes 
Y  are  those  which  admit  the  cold  water  to  the 
coolers,  and  P  those  returning  the  heated  water  to  the 
waste  receiver.  At  V  V  V  are  seen  some  of  the  many 
coolers  which  are  built  in  the  furnace  lining  to  preserve 
its  life.  In  the  furnace  shown  these  are  placed  in 
layers  about  thirty  inches  apart  in  height,  and  has 
about  two  feet  of  space  between  them.  Some  furnaces 
have  them  built  much  closer  than  this,  both  in  height 


CONSTRUCTION    OF    BLAST    FURNACES.  39 

and  circumference.  There  are  various  plans  of  coolers 
used  with  furnaces.  The  coolers  here  illustrated  are 
made  of  cast-iron  about  three  inches  thick  by  two  feet 
square,  and  each  has  three  independent  coils  of  one 
and  one-half  inch  pipe  cast  in  it,  so  arranged  that 
should  the  front  coil  be  attacked  by  the  heat  as  it 
burns  out  the  lining",  it  can  be  shut  off,  and  the  inner 
coils  be  made  operative  independently  or  as  a  whole. 
Some  furnaces  have  these  coolers  made  of  bronze,  cast 
hollow.  It  is  very  seldom  trouble  is  experienced  with 
the  coolers  shown,  and  if  any  should  occur  arrange- 
ments permit  their  being  taken  out  and  replaced.  At 
L  is  seen  a  two-inch  pipe,  perforated  with  one-eighth 
inch  holes  about  two  inches  apart,  which  encircles  the 
furnace  and  keeps  a  constant  stream  of  cool  water  run- 
ning down  the  plate  I  which  supports  the  hearth 
portion  of  the  furnace.  This  water  runs  down  on  the 
outer  surface  of  the  plate  to  a  reservoir  at  R,  and 
which  can  be  filled  up  with  water  to  a  height  of  about 
three  feet,  to  protect  the  lower  portion  of  the  hearth 
with  a  heavy  body  of  water.  A  valve  is  so  arranged 
in  the  reservoir  R  that  any  height  of  water  can  be 
maintained  in  it.  It  is  no  unusual  occurrence  for  the 
metal  to  break  out  at  this  portion  of  a  furnace,  result- 
ing in  much  injury  to  life  and  property.  The  furnace- 
man's  lot  is  by  no  means  one  any  need  envy,  for  he 
shares  very  fairly  the  troubles  and  dangers  he  has  who 
1 '  meddles  with  hot  iron. ' ' 


CHAPTER  IV. 

LINING  AND  DRYING  OF    FURNACES. 

Methods  of  lining  a  furnace  and  the  shape  of  the 
bricks  have  as  much  to  do  with  the  life  of  the  lining  as 
other  qualities  denned  in  this  chapter.  It  is  very 
expensive  to  line  a  modern  furnace,  and  when  com- 
pleted it  should  give,  at  least,  a  continuous  service  of 
two  years  with  hard  ores  and  three  years  with  soft 
ores,  and  this  length  of  service  may  often  be  doubled. 
When  it  is  stated  that  450  tons  of  fire-brick  and  60  of 
fire-clay,  or  a  heavily  laden  train  of  about  twenty-five 
cars  of  material,  are  necessary  to  line  such  a  furnace 
as  seen  in  Fig.  10,  the  magnitude  of  such  a  job,  as 
compared  with  lining  even  our  largest  cupolas,  can  be 
readily  perceived.  Bricks  for  a  furnace  are  largely 
made  to  order,  so  as  to  neatly  fit  its  curves,  slant,  or 
circle  which  the  form  of  the  shell  or  inside  of  the 
lining,  etc.,  may  exact.  This  is  done  so  as  to  have 
all  joints  fit  as  closely  as  possible  without  cutting 
bricks  or  filling  in  the  clay.  Bricks  of  a  softer  quality 
than  those  used  for  the  stack  portion  of  the  furnace  are 
desired  for  the  hearth  and  bosh,  as  the  former  are 
exposed  to  greater  destruction  from  friction,  while 
those  in  the  hearth  and  bosh  portion  are  chiefly  sub- 
jected to  the  action  of  heat.  Such  a  quality,  if  used  in 
the  stack  portion,  though  its  composition  is  best  able 
to  withstand  the  heat,  would  soon  wear  away  by  the 


LINING    AND    DRYING    OF    FURNACES.  4> 

constant  friction  of  the  stock,  so  that  better  service  is 
found  by  sacrificing  the  heat  qualities  to  those  best 
calculated  to  withstand  friction  for  stack  linings. 

In  laying  bricks,  a  thin  grouting  of  the  best  fire-clay, 
without  mixture  of  sand,  is  used.  The  clay  is  mixed 
of  such  consistency  that  a  brick,  if  dipped  into  it, 
would,  upon  being  lifted  out,  have  a  coating  of  about 
one-eighth  of  an  inch  adhere  to  it.  To  make  a  bed  of 
clay  for  the  brick  to  be  laid  in,  a  dipper  is  used  to  pour 
the  clay  upon  the  surface  of  the  last  course,  laid  to  a 
thickness  of  about  one-fourth  of  an  inch.  The  bricks 
are  then  slid  on  soft  clay  up  to  each  other  so  as  to 
imbed  themselves  firmly,  and  closely  force  the  clay 
between  all  joints,  after  which  a  hammer  is  used  to 
crowd  the  joints  still  more  closely  together  or  bed 
the  bricks  more  firmly.  In  order  to  obtain  a  true 
circle  when  lining  the  hearth,  bosh,  and  stack  of  a 
furnace,  a  plumb  bob-line  is  dropped  from  the  top  to 
obtain  a  center  for  a  ' '  spindle  ' '  with  a  * '  sweep  ' ' 
attached,  which  is  to  be  carried  up  as  the  work  pro- 
gresses, just  as  a  loam  moulder  would  build  a  large 
cylinder  mould.  The  time  usually  occupied  in  lining 
such  a  furnace  as  shown  in  Fig.  10,  employing  four 
masons  and  twelve  helpers,  is  about  thirty  days. 
The  work  of  lining  a  furnace  is  considered  a  specialty, 
and  the  leading  men  in  such  work  are  carefully 
selected  from  those  having  the  greatest  experience  in 
this  line,  as  any  faulty  construction  can  easily  result 
in  a  very  short  run  of  a  furnace,  thus  causing  a  great 
expense  in  ' '  blowing  out ' '  to  remedy  the  evil. 

Space  for  expansion  of  fire=brick,  as  illustrated  at 
K,  Fig.  6,  and  both  sides  of  Fig.  10,  page  49,  is  a 
practice  now  followed  in  lining  furnaces.  This  space 


42  METALLURGY    OF    CAST    IRON. 

ranges  from  three  to  four  inches  in  width,  and  in 
length  from  the  bosh  portion  up  to  the  top  of  the 
stack,  as  shown,  the  hearth  being  built  solid,  as  seen  in 
the  sketch.  A  material  now  extensively  used  for  filling 
this  expansion  space,  K,  is  the  slag  of  a  furnace,  after 
being  granulated  by  the  action  of  water.  A  loamy 
sand  was  at  one  time  used,  but  it  packs  too  firmly. 
Then,  again,  a  coarse  class  of  sharp  sand  has  been 
used,  but  the  slag  as  above  prepared  has  been  found 
the  best.  Experience  has  proven  the  necessity  of  such 
a  system,  as  several  furnaces  have  had  their  shells 
ruptured  by  the  expansive  force  of  fire-bricks  when 
not  permitted  room  to  swell  from  the  effects  of  the 
heat.  Not  only  have  furnaces  provided  for  this  lateral 
expansion,  but  also  for  longitudinal  strains  as  well,  as 
such  action  has  been  known  to  press  the  brick-work, 
bell,  hopper,  and  charging  platform  upward  from 
three  to  four  inches  above  the  top  of  the  shell,  or  its 
original  level.  All  the  iron  work  at  the  top  of  a  fur- 
nace is  constructed  independent  of  the  shell,  so  as  to 
liberate  it  from  all  strain  when  longitudinal  expansion 
takes  place. 

Drying  a  furnace  becomes  necessary  before  it  is 
charged  for  "blowing  in."  There  are  several  meth- 
ods of  doing  this.  One  is  by  building  a  fire  inside  the 
furnace ;  another  by  constructing  a  fire-place  outside, 
at  the  breast  portion,  and  letting  the  heat  from  the 
same  pass  into  the  furnace ;  still  another  by  the  admis- 
sion of  natural  gas,  or  the  gas  from  the  ovens  of 
another  furnace,  should  two  or  more  furnaces  be  near 
each  other.  The  objection  to  building  a  fire  inside  a 
furnace  is  that  the  dirt  and  ash  which  it  creates 
requires  considerable  labor  to  clean  out,  and  requires 


LINING    AND    DRYING    OF    FURNACES.  43 

more  fuel  than  by  any  other  plan,  but  is  quicker  in  its 
action  of  drying.  After  a  fire  has  been  well  started, 
all  holes  around  the  furnace  and  the  top,  with  the 
exception  of  a  "bleeder"  H,  Fig.  13,  page  57,  of 
about  twelve  inches  diameter,  are  closed,  the  ' '  bleeder  ' ' 
being  left  open  to  create  draft.  The  time  taken  to 
dry  a  furnace  ranges  from  one  to  four  weeks. 

The  life  of  a  furnace  lining  not  only  depends  upon 
qualities  described  in  preceding  paragraphs,  but  also 
upon  the  manner  in  which  a  furnace  is  worked.  Those 
that  are  driven  hard  by  high  blast  pressures,  to  get 
the  greatest  possible  output  of  iron,  have  not  nearly 
the  life  of  those  driven  more  mildly.  America  is  noted 
for  fast  driving  to  attain  greatest  output.  For  this 
reason  if  furnaces  run  steadily  for  five  years  in 
our  country  they  are  doing  very  excellent  work, 
whereas  in  Europe  furnaces  have  run  steadily  for  ten 
to  fifteen  years;  although  they  are  commencing  to 
drive  them  faster  than  formerly. 

One  factor  of  great  protection  to  linings  exists  in 
the  formation  of  a  kind  of  graphite  or  carbonaceous 
concrete  which  accumulates  on  the  face  of  the  lining; 
this  comes  from  the  kish,  slag,  and  carbon  refuse  gener- 
ated in  the  furnace,  which  may  be  found  two  to  twelve 
inches  thick  on  the  lining,  the  greatest  thickness  being 
found  in  the  hearth  or  lower  body  of  a  furnace. 

The  factors  which  destroy  the  life  of  furnace  linings 
are  defined  under  four  heads  by  Fritz  W.  Lurmann  in 
the  Journal  of  the  Iron  and  Steel  Institute,  1878,  Vol. 
I.,  page  200,  as  follows: 

"  i.  The  actual  wear  due  to  contact  with  the  descending 
charge.  This  is  relatively  unimportant.  2.  The  actions  of  the 
alkaline  cyanides  and  other  substances  present  in  the  furnace 


44  METALLURGY    OF    CAST    IRON. 

gases  which,  though  probably  important,  produce  an  effect  the 
amount  of  which  is  at  present  not  accurately  determined.  3. 
The  action  of  sodium  chloride  or  other  alkaline  substances  con- 
tained in  coke ;  this  is  probably  one  of  the  most  important  causes 
of  wear,  as  at  a  high  temperature  salt  is  decomposed  by  silica, 
and  a  fusible  silicate  is  obtained.  4.  The  flaking  of  the  bricks 
due  to  decomposition  of  carbon  from  carbon  monoxide  around 
any  iron  particles  reduced  from  impurities  in  the  original  bricks. ' ' 

The  best  grades  of  fire-brick  are  necessary  in  lining 

furnaces.  Absolute  fire-proof  bricks,  it  may  be  said, 
are  not  obtainable.  Several  kinds  of  material  have 
been  tried  in  an  effort  to  secure  a  lining  for  furnaces 
that  would  exceed  the  life  of  the  general  character  of 
fire-bricks  used.  We  have  what  are  called  silica,  car- 
bon, ganister,  coke,  magnesia,  and  asbestos  bricks,  all 
of  which  have  been  experimented  with,  and,  to  some 
degree,  all  have  advocates  of  their  utility  in  certain 
lines  of  work.  Carbon  bricks,  it  is  claimed,  have  worn 
well,  made  of  fine  coke  (poor  in  ash),  or  charcoal  mixed 
with  clay  with  tar  as  a  binder.  If  such  bricks  contain 
more  than  70  per  cent  of  silica,  as  used  for  high 
temperatures,  they  are  generally  very  friable  and 
disintegrate  with  the  least  friction,  so  that  bricks  of 
this  character  would  be  suitable  only  for  the  lower 
body  of  a  furnace.  As  clay  is  chiefly  silicate  of 
alumina,  which  is  also  a  good  substance  to  resist  high 
temperatures,  it  works  well  as  a  binder  with  silica  in 
making  fire-bricks.  The  other  substances  in  clay  are 
iron  oxide,  lime,  magnesia,  potash  and  soda,  which,  to 
some  degree,  decrease  the  durability  of  fire-bricks. 
As  fire-bricks  come  to  the  furnace 'or  foundry  they  are 
often  composed  of  about  equal  parts  of  silica  and 
alumina.  Bricks  should  contain  silica  or  alumina  in 
proportion  to  the  amount  of  heat  or  friction  they  are 


LINING    AND    DRYING    OF    FURNACES.  45 

required  to  withstand.  The  life  of  fire-brick  depends 
upon  the  purity  of  these  ingredients.  The  silica 
should  be  pure  quartz  or  anhydrous  silica,  and  not 
uncalcined  or  raw  rock  for  a  substitute  as  is  often 
practiced  by  some.  It  can  be  readily  seen  that  onr 
kind  of  fire-brick  may  give  excellent  service  with  one 
character  of  work  and  very  poor  for  others. 


CHAPTER  V. 

OPERATING  BLAST    FURNACES   AND  RE- 
DUCTION OF  ORES. 

The  amount  of  stock  that  passes  through  a  furnace 
the  size  of  that  seen  in  Fig.  10,  page  49,  every  twenty- 
four  hours  is  about  280  tons  of  ore,  190  tons  of  coke, 
and  60  tons  of  limestone,  a  total  of  530  tons.  In  filling 
a  furnace  by  hand  labor,  two  gangs  of  men  are  always 


FIG.   7. —  MODERN    BLAST   FURNACE  WHERE   HAND  LABOR    IS   MINIMIZED. 

employed,  one  at  the  top,  and  the  other  on  the  ground 
floor  load  the  buggies  and  wheel  them  to  the 
elevator,  which  ascends  a  distance  of  70  to  100  feet  in 
about  twenty  seconds.  There  being  two  cages  to  the 
elevator,  an  empty  one  is  returned  as  the  loaded  one 


OPERATING    BLAST    FURNACES. 


47 


ascends.  The  buggies  used  hold  about  800  pounds  of 
ore  and  of  coke  450  pounds.  The  men  charging  the 
furnace  are  called  * '  top  fillers  ' '  and  those  loading  the 
buggies  ' '  bottom  fillers. ' '  The  work  is  thoroughly 
systematized,  each  man  knowing  his  part.  Top  fillers 
hold  a  somewhat  hazardous  position,  as  it  is  not  uncom- 
mon for  men  to  be  ' '  gased  ' '  by  the  fumes  escaping  at 
the  bell  and  hopper  of  a  furnace.  Some  furnaces 
suspend  a  sheet  iron  stack  about  ten  feet  over  the  top 


FIG.   8.  — HOISTING    APPARATUS   OF    A    MODERN   FURNACE  —  LABOR   ALL 
ACCOMPLISHED    BY    MACHINERY. 

of  the  bell,  on  the  charging  platform,  for  creating  a 
draught  to  carry  off  the  escaping  gases.  Improve- 
ments have  been  made  whereby  all  stock  is  carried  up 
and  dumped  by  machinery  into  the  hopper,  so  that 
there  is  no  need  for  men  working  on  a  furnace  as  '  *  top 


OPERATING    BLAST    FURNACES. 

fillers. ' '  A  view  of  this 
more  modern  plan  of 
charging  a  furnace  is 
shown  in  Figs.  7  and  8, 
and  which  are  illustra- 
tions used  by  Mr.  Walter 
Kennedy  in  the  A  merican 
Manufacturer,  January 
3,  1901.  We  also  present 
cut  Fig.  9,  which  was 
originally  shown  in  the 
Journal  of  the  Associa- 
tion of  Engineering  So- 
cieties, January,  1901. 

In  charging  a  furnace, 
the  coke,  limestone,  and 
ore  are  generally  dumped 
in  the  order  mentioned 
and  dropped  independ- 
ently of  each  other  in  the 
hopper  H,  Fig.  10.  Af- 
ter the  completion  of  each 
charge,  the  bell  B  is  then 
lowered  as  indicated,  and 
the  material  falls  into  the 
furnace  shown,  about  as 
illustrated  at  the  mound 
M  M.  After  the  delivery  Slagllole 
of  the  charge,  the  bell 
returns  to  its  position, 
ready  to  receive  the  next 
supply  of  stock.  There 
are  several  ways  of  oper-FIG  I0. -ACTION  OF  STOCK  DESCENDING 

A  FURNACE. 


METALLURGY    OF    CAST    IRON. 


FIG.  II. 


ating  the  bell,  but 
the  method  used  with 
the  furnace  shown  is 
that  of  moving  the 
beam  S  up  and  down 
by  means  of  a  piston 
D,  which  can  be 
operated  by  steam  or 
the  blast  pressure. 
The  bell  must  be 
hung  true,  since,  if 
one  side  should  swing 
lower  than  the  other,  when  the  stock  is  admitted  to 
the  furnace,  the  charge  would  lodge  unevenly  and 
have  a  tendency  to  cause  scaffolding  and  other  evil 
results,  similar  to  uneven  charging  of  stock  in  a  cupola. 
Where  the  bell  and  hopper  are  used  for  charging 
stock,  the  angle  and  diameter  of  each,  as  compared 
with  the  diameter  of  the  furnace  at  its  throat  or  stock 
line,  have  all  to  do  with  the  form  and  position  which 
stock  assumes  when  dropped  into  it.  The  angle  of  the 
hopper  influences 
that  of  the  bell  in  de- 
termining  the  distri- 
bution and  position 
of  coarse  and  fine  ma- 
terial, also  the  forma- 
tion of  the  irregulari- 
ties in  mounds  which 
a  charge  may  as- 
sume, after  being 
dropped  by  a  bell  in- 
to a  furnace.  It  is 


OPERATING    BLAST    FURNACES.  5! 

generally  conceded  that  the  small  bell,  as  in  Fig.  n, 
sends  the  coarse  material  to  the  outside  circle,  while 
the  larger  bell,  Fig.  12,  sends  it  to  the  inner  circle, 
and  the  coarse  material  may  descend  faster  than  the 
fine  stock.  Furnacemen  are  now  largely  using  small 
bells. 

The  action  of  stock  in  passing  down  through  a  fur- 
nace should  attain,  if  possible,  an  occasional  shifting 
movement,  so  as  to  retard  the  formation  of  any  solid 
mass  of  the  stock.  This  is  best  achieved  in  a  taper 
stack,  as  the  stock  in  passing  downward  should  assume 
an  action  somewhat  similar  to  that  illustrated  in  the 
various  levels,  A,  B,  C,  D,  E,  and  F,  seen  in  Fig.  10, 
page  49.  When  stock  is  dropped  by  a  bell,  such  as  in 
the  size  of  the  furnace  shown,  it  is  generally,  if  all  is 
working  well,  distributed  in  a  form  somewhat  like  that 
in  the  mounds  M  M,  seen  at  the  level  A,  which  is  called 
the  "  stock  line,"  and  is  generally  ten  feet  below  the 
level  of  the  bell.  The  stock  in  settling  down  to  fill 
the  increasing  diameter  of  a  tapering  stack  must  have 
a  spreading  out  or  leveling  action  taking  place,  or  in 
other  words,  the  outside  would  descend  faster  than  the 
inside  stock.  It  seems  reasonable  that  the  tendency 
of  the  stock  in  settling  would  be  to  have  the  angles 
constantly  leveling  themselves  somewhat  after  the 
idea  illustrated  at  the  various  strata  B,  C,  D,  and  E, 
Fig.  10,  until  it  has  reached  the  bosh  at  F,  when  reac- 
tion would  take  place  and  the  stock  in  descending  would 
be  retarded  by  the  walls  of  decreasing  diameter  and 
cause  the  center  portion  to  travel  faster  than  the  side, 
until  at  the  last  stratum,  I,  the  center  stock  would 
have  traveled  ahead  of  the  side  stock  as  shown  at  R. 
Before  this  point  is  reached,  however,  the  reaction 


52  METALLURGY    OF    CAST    IRON. 

(which  changes  the  oxide  of  iron  in  the  ore  to  metallic 
iron,  and  carbonizes  it  to  form  cast  iron)  has  taken 
place  and  all  the  stock  is  liquefied,  gases  have  escaped, 
and  what  passes  to  the  point  Y  is  some  remaining  fuel 
which  replenishes  the  bed  over  the  melted  iron  and 
slag.  The  total  length  of  line  at  the  different  levels, 
B,  C,  D,  and  E,  is  the  same.  In  cupola  practice, 
foundrymen  have  the  advantage  over  furnacemen  in 
being  able  to  observe  the  action  of  the  stock  until  it 
has  reached  the  "  melting  point."  In  observing  stock 
settle  at  the  last  charge  in  a  straight  cupola,  when  all 
is  working  well,  little  or  no  change  is  noticed  in  the 
position  of  the  material,  and  this  is  generally  so  true 
that  the  founder  knows  that  whatever  way  stock  is 
delivered  into  a  cupola  it  will  generally  be  found  so 
situated  when  it  reaches  the  ' '  melting  point. ' '  For 
this  reason  founders  often  have  experience  with 
"  bunged-up  "  cupolas  or  iron  dumped  at  "bottom- 
drop,  ' '  which  could  not  be  melted  owing  to  fuel  or  iron 
not  having  been  charged  evenly.  Often  stock  reaches 
the  melting  point  with  fuel  mostly  on  one  side  and 
iron  on  the  other  through  carelessness  in  charging  in 
that  manner. 

In  the  descent  of  the  stock,  coke,  limestone,  and  ore, 
all  moisture  is  driven  off,  the  thoroughly  dry  and 
heated  ore  now  comes  in  the  zone  of  reduction,  where 
the  oxygen  is  taken  from  it,  and  changed  from  oxide 
of  iron  to  metallic  iron,  during  which  process  the  iron 
takes  up  carbon  from  the  fuel,  and,  melting  in  the  zone 
of  fusion,  finally  arrives  at  the  bottom  in  form  to  be 
tapped  out.  The  non-metallic  or  earthy  matter,  in 
separating  from  the  reduced  iron,  unites  with  the  lime 
or  flux  and,  being  lighter  than  iron,  floats  on  its  surface 


OPERATING    BLAST    FURNACES.  53 

and  is  tapped  off  as  slag  through  the  slag  hole  T,  Fig. 
10,  page  49,  while  the  iron  is  delivered  at  the  tap  hole 
X.  The  amount  of  fuel  and  limestone  necessary,  de- 
pends upon  the  nature  of  the  ore  charged  and  the  grade 
of  iron  desired.  All  material  charged  into  a  furnace 
passes  off  either  as  a  liquid  or  as  a  gas.  The  gas  which 
comes  off  at  the  top  is  made  to  pass  through  the  down 
comer  into  the  ovens  and  burned  there.  There  the 
blast  is  heated  while  passing  to  the  furnace.  The 
liquid  products  which  pass  off  are  iron  and  slag,  both 
formed  at  a  point  ranging  from  a  level  with  the  tuyeres 
to  a  height  of  about  four  feet  above  them,  a  portion 
generally  called  the  "  melting  zone,"  or  bosh,  the  hot- 
test part  of  a  furnace. 

If  ore  is  not  properly  reduced  a  percentage  of  its  iron 
may  pass  off  with  the  slag,  the  reason  for  this  being 
that  it  is  not  thoroughly  extracted  from  the  ore  and 
non-metallic  matter.  This  is  generally  due  to  an 
insufficient  amount  of  fuel,  or  decrease  in  temperature 
from  other  causes.  Moreover,  too  small  an  amount  of 
silicon  is  reduced  at  the  same  time  from  the  fuel  and 
ore,  and  consequently  the  iron  obtained  is  smaller  in 
amount  and  silicon  contents  and  richer  in  sulphur. 
The  furnace  is  working  cold,  or  "off,"  and  a  greater 
per  cent  of  fuel  may  make  it  work  better. 

Sulphur  in  iron  is  generally  largely  obtained  from 
the  fuel  in  a  furnace.  Iron  from  the  ore,  as  well  as 
the  lime  in  the  flux  absorbs  sulphur.  Which  of  these 
two  elements,  in  the  process  of  reducing  the  ore,  will 
absorb  the  greater  percentage  of  sulphur  from  the  fuel 
depends  upon  the  degree  of  heat  obtained.  Lime  has 
a  great  affinity  for  sulphur,  and  if  the  slag  is  made 
thin  and  hot  it  can  counteract  the  absorbing  power  of 


54  METALLURGY    OF    CAST    IRON. 

the  iron  and  take  much  of  the  sulphur  itself.  If  the 
furnace  is  working1  cold  so  as  not  to  properly  fuse  the 
limestone,  then  the  iron  will  absorb  and  retain  higher 
sulphur ;  and  hence  the  greater  sulphur  found  in  the  iron 
coming  from  a  coldworking  furnace,  which  often 
results  in  giving  a  hard  or  ' '  white  iron. ' '  The  way 
high  silicon  and  low  sulphur  iron,  or  No.  i  pig  iron,  is 
generally  obtained  is  by  having  a  hot  furnace,  well  but 
not  excessively  fluxed  with  lime.  To  make  high  silicon 
and  high  sulphur  iron,  as  is  often  obtained,  it  is  neces- 
sary to  have  a  hot  furnace  poorly  fluxed  with  lime.  A 
cold  furnace  gives  a  thick,  bad  slag,  the  same  as  a  cold 
cupola  retards  good  fluxing  or  slagging  out.  A  good 
working  furnace  sends  the  most  silicon  into  the  pig 
and  sulphur  into  the  slag;  a  poor  working  furnace 
reverses  these  conditions. 


CHAPTER  VI. 

CAUSE  AND  EVILS  OF  SCAFFOLDING  AND 
SLIPS  IN  A  FURNACE. 

The  factors  causing  the  greatest  irregularity  in  the 

working  of  a  furnace  are  scaffolding  and  slips.  This 
means  that  a  portion  of  the  stock  will  hang  at  one 
point  for  a  period  and  then  suddenly  becoming  loos- 
ened, will  slip  for  a  distance  and  reach  material  filling 
the  bottom  or  hearth  of  a  furnace.  There  are  four 
factors  effecting  the  hanging  of  stocks  and  slips,  which 
.are  evils  all  furnacemen  aim  to  overcome.  The  first 
of  these  is  the  lines  of  the  furnaces,  the  second  the  man- 
ner in  which  the  stock  is  delivered  to  the  furnace,  the 
third  the  quality  or  nature  of  the  ore  and  fuel  used,  and 
the  fourth  the  state  of  the  temperature  of  the  blast  and 
atmosphere  causing  a  furnace  to  work  cold  or  hot.  A 
few  years  ago  experts  said  that  the  Messabi  ores  could 
not  be  smelted  in  a  furnace,  owing  to  their  being  so  fine 
and  loamy.  But  the  large  percentage  of  iron  which 
they  contain,  their  low  phosphorus,  (which  makes  it  a 
good  ore  for  Bessemer,)  and  low  sulphur,  three  very 
desirable  elements,  combined  with  low  cost,  caused 
furnacemen  to  try  it  and' persevere  in  its  use,  until 
to-day  it  is  a  large  percentage  of  the  ores  charged  into 
many  furnaces.  Nevertheless,  furnacemen  find  much 
trouble  from  slips  and  wastage  of  this  ore  in  the  form 
of  fine  dust  being  carried  out  with  the  gases  through 


56  METALLURGY    OF    CAST    IRON. 

the  "down-comers."  There  is  much  study  being 
given  in  hopes  to  devise  methods  to  overcome  these 
difficulties.  To  help  matters,  a  few  have  taken  out 
their  old  bells  and  replaced  them  with  smaller  ones, 
and  they  report  a  very  commendable  improvement  in 
preventing  slips  when  iising  Messabi  ores. 

The  reason  for  stock  scaffolding  in  a  furnace  is  often 
found  in  the  irregularity  of  the  lining.  The  constant 
friction  of  the  stock  in  working  downward  cuts  cavi- 
ties into  the  lining,  often  forming  regular  shelves 
upon  which  the  stock  can  easily  hang  up.  The  longer 
a  furnace  runs,  the  more  favorable  conditions  become 
to  scaffolding,  and  when  it  is  stated  that  ore  is  a  sub- 
stance which  becomes  gummy  and  swollen  before  it  is 
reduced  to  a  fluid  state,  one  can  readily  perceive  why 
such  trouble  may  be  expected  in  a  furnace,  causing  an 
irregularity  in  the  product,  and  at  times  disarranging 
all  calculations  of  the  furnaceman  by  producing  an 
undesired  character  of  iron.  When  furnacemen 
experience  trouble  with  scaffolding,  etc.,  not  due  to  a 
hot  furnace,  as  described  in  Chapter  X.,  page  75,  they 
often  resort  to  the  use  of  more  fuel  than  when  all  is 
working  well.  The  additional  percentage  of  fuel 
causes  a  greater  heat,  making  the  stock  more  plastic, 
and  causing  it  to  give  way  more  easily  from  the  walls 
of  a  furnace.  It  generally  takes  from  five  to  ten 
hours  for  stock  to  work  down  from  the  top  to  be 
tapped  out  as  iron. 

A  slip  in  a  furnace  often  means  the  falling  of  from 
twenty-five  to  two  hundred  tons  of  stock  from  a  height 
of  one  to  fifteen  feet.  The  contemplation  of  this  tak- 
ing place  within  a  furnace  filled  with  combustible 
gases,  heated  stock,  and  liquid  metal  should  enable 


CAUSE    AND    EVILS    OF    SCAFFOLDING,     ETC. 


57 


Vfi 


dia. 

Charging 

any  one  to  form  some  conception  of  the  damage  that 
could  be  done,  and  the  reason  all  hands  around  a  fur- 
nace have  good  cause  to  fear  a  slip.  The  scaffolding 
of  a  furnace  can  prove  so  disastrous  as  to  disable  or 

make  unsafe  its  work- 
ing parts.  The  au- 
thor has  seen  a  slip 
cause  such  an  explo- 
sion as  to  lift  the  bell 

f~<0 

~*--B  and  hopper  F.  and  K, 
Fig.  13,  throwing 
them  out  almost  on 
top  of  the  furnace  plat- 
form, and  straining  it 
to  such  an  extent  that 
it  was  a  question 
whether  it  was  safe  to 
rely  on  the  furnace 
shell ;  and  he  has  heard 
of  a  bell  and  hopper 
being  thrown  about 
twenty  feet  from  a 
furnace.  Plans  have 
been  adopted  to  re- 
lieve sudden  gas  pres- 
sure, some  of  which 
are  working  very  satis- 
factorily, especially  the 
system  used  at  the  Alice  Furnace,  Sharpsville,  Pa., 
designed  and  patented  by  Mr.  P.  C.  Reed,  the 
furnace  superintendent,  and  shown  in  Fig.  13.  The 
idea  is  to  build  four  large  openings  equally  divided 
around  the  circumference  within  a  few  feet  of  the 


FIG.  13. 


$8  METALLURGY    OF    CAST    IRON. 

top  of  the  stack.  These  are  connected  with  flues 
branching  upward  about  eight  feet  high,  and  closed 
by  means  of  valves  hung  on  pivots,  as  seen  at  H  H, 
and  so  regulated  by  weight  that  they  will  open  of 
themselves  when  any  excess  of  pressure  is  created 
in  the  furnace.  -This  improvement  is  a  step  forward  in 
furnace  practice  which  diminishes  the  risks  of  accidents 
and  loss  of  life,  but  it  still  remains  to  better  guard 
against  the  evils  of  scaffolding  or  the  slipping  of  stock 
so  detrimental  to  successful  furnacing,  often  requiring 
several  days  after  a  slip  to  get  a  furnace  back  again  to 
working  satisfactorily  and  give  a  fair  uniform  grade 
of  iron. 


CHAPTER  VII. 

COMPOSITION  AND  UTILITY  OF  FLUXES. 

The  object  of  fluxing  furnaces  and  cupolas  is  to  give 
fluidity  to  the  non -metallic  residuum  of  the  iron  ore 
and  the  ash  of  the  fuel,  to  carry  it  out  of  the  furnace 
or  cupola  in  the  form  of  slag.  While  this  is  an  impor- 
tant function,  there  are  certain  chemical  compositions 
tkat  can  exist  in  fluxes  which  best  assist  in  obtaining 
desired  results,  similar  as  there  are  certain  chemical 
constituents  necessary  in  ores  to  obtain  the  brands  or 
grades  of  iron  desired.  All  fluxes  should  be  as  free  of 
earthy  matter  as  possible,  since  such  retards  their 
action.  High  silica  and  sulphur  are  likewise  objection- 
able. The  element  most  essential  in  a  flux  to  aid  the 
creation  of  slag  is  lime.  This  is  found  in  various  sub- 
stances, as  in  marble,  spalls,  oyster  and  clam  shells, 
limestone,  chalk,  dolomite,  calc-spar,  fluor-spar,  and 
felspar. 

Magnesia  largely  serves  the  same  end  as  lime,  but 
less  of  it  is  required.  About  two  of  the  former  is 
sufficient,  where  three  of  the  latter  would  be  required. 
Dolomite  contains  more 'magnesia  than  any  other  class 
of  limestone,  and  is  often  called  magnesia  limestone 
and  generally  contains  about  55  per  cent  of  calcium 
carbonate  and  40  per  cent  of  magnesium  carbonate, 
with  the  rest  largely  silica,  oxide  of  iron,  and  alumina. 


60  METALLURGY    OF    CAST    IRON. 

Dolomite  is  now  being  used  in  the  making  of  high 
silicon  and  other  irons,  but  it  is  said  it  is  not  as  effec- 
tive in  lowering  sulphur  in  iron  as  limestone  where 
sulphur  is  troublesome. 

The  more  silica  a  flux  contains  the  greater  fuel  or 
higher  temperature  required  to  fuse  it  and  the  less  its 
value  as  a  flux,  for  the  reason  that  more  lime  is 
required  to  unite  with  the  silica  to  make  a  good  slag, 
and  the  more  silicious  the  ore  the  more  lime  generally 
required  to  flux  it.  It  has  been  known  to  require 
more  lime  than  there  was  ore  charged  in  order  to  flux 
the  high  silica  which  the  ore  contained.  Silica  as 
found  in  slag  is  not  only  derived  from  the  fuel  and 
ore,  but  also  from  the  scale  and  sand  of  any  iron  which 
may  be  charged  into  a  furnace  or  cupola,  and  from  the 
oxidation  of  the  silicon  in  iron  during  the  heat.  It  is 
to  be  remembered  that  the  more  lime  a  flux  contains, 
the  better  it  serves  the  end  of  creating  slag  to  affiliate 
with  the  earthy  matter  and  debris  formed  in  a  furnace 
or  cupola,  and  also  the  more  silica  or  lime  there  is  in 
a  furnace  or  cupola,  the  more  fuel  required  to  smelt  or 
melt  the  iron.  Alumina  is  also  pronounced  in  its 
effects  upon  the  decrease  or  increase  of  the  fluidity  of 
the  slag.  As  a  general  thing,  the  more  alumina  the 
higher  the  temperature  required  to  fuse  the  flux  in 
order  to  make  a  good  liquid  slag. 

The  following  Table  10  is  a  compilation  of  fluxes 
which  the  author  has  used  with  good  results,  and  will 
serve  to  illustrate  the  physical  as  well  as  the  chemical 
properties,  and  will  also  show  that  a  flux  which  might 
work  well  in  a  furnace  can  often  be  well  utilized  in 
cupola  practice : 


COMPOSITION    AND    UTILITY    OF    FLUXES. 


6l 


TABLE    IO. 


No.  i. 

No.  2. 

No.  3. 

Silica  

3.00 

1.98 

•54 

[ton  Oxide  

.92 

.60 

.12 

Alumina          „ 

1  .25 

.QO 

-6 

Phosphorus 

Sulphur 

Carbonate  of  Lime  

92.  10 

82.8s 

98.78 

Carbonate  of  Magnesia 

1.26 

Lime  Oxide   

ci.cy 

CC.-52 

Magnesium  Oxide 

1.  61 

The  physical  character  of  No. .  i  is  very  hard  and  of  a 
dark  color,  and  is  a  grade  of  limestone  largely  used 
for  blast  furnaces.  It  is  obtained  near  New  Castle, 
Pa.  No.  2  is  of  a  much  softer  quality  than  No.  i  and 
also  more  white  and  clear  in  its  color.  It  is  known  as 
Kelly  Island  limestone  and  is  mined  at  Marblehead 
and  Lakeside,  O.  No.  3  is  softer  and  purer  in  color 
than  either  Nos.  i  or  2  and  has  something  of  a  checked 
marble  cast.  It  is  obtained  from  the  Benson  Mines, 
New  York,  and  instead  of  being  called  limestone  as 
are  the  first  two  shown,  it  is  defined  as  calcite  by  the 
shippers.  It  will  be  noticed  that  Nos.  2  and  3  have 
no  sulphur.  For  many  classes  of  work  this  is  prefer- 
able to  No.  i  As  sulphur  in  limestone  is  similar  in 
its  effect  to  sulphur  in  fuel,  it  largely  passes  into  the 
iron  and  raises  its  sulphur  contents.  For  cupola  work 
preference,  as  far  as  labor  is  concerned,  would  be 
given  to  Nos.  2  and  3  owing  to  these  being  more 
friable  than  No.  i,  but  the  furnace  limestone  No.  i  is 


62  METALLURGY    OF    CAST    I.RON. 

less  expensive.  All  the  above  fluxes  are  used  just  as 
they  are  mined,  being  in  no  way  burned  or  roasted  — 
a  treatment  necessary  to  some  grades  of  limestone  — 
and  will  benefit,  it  is  claimed,  almost  any  flux  of  a 
rock  character.  When  this  is  done  with  limestone  it 
gives  us  quicklime,  a  form  that  requires  less  weight 
when  charged  than  limestone.  The  action  of  burning 
or  roasting  causes  the  limestone  to  become  friable,  so 
as  to  largely  eliminate  its  carbonic  acid  and  other 
volatile  matter  and  generally  make  a  limestone  more 
ready  to  unite  with  the  impurities.  While  such  treat- 
ment of  limestone  would  naturally  be  expected  to  be 
economical,  it  has  not  proven  so  in  all  cases.  When 
the  fuel  required  to  roast  it  is  taken  into  consideration 
with  that  which  may  be  saved  in  converting  it  into 
slag  in  the  smelting  of  iron,  there  is  considerable 
difference  of  opinion  in  regard  to  the  question  of 
economy  for  furnace  practice. 


CHAPTER  VIII. 

FLUXING  AND  SLAGGING  OUT  FUR- 
NACES 

The  percentage  of  ore  and  fuel  which  must  be  carried 
off  by  the  slag  in  making-  iron  consists  of  ten  to  thirty 
per  cent  of  the  former  and  ten  to  fifteen  per  cent  of 
the  latter.  A  portion  of  this  extraneous  matter  is 
basic,  the  rest  acid.  The  chemical  affinity  thus  exist- 
ing is  such  that,  when  this  material  is  subjected  to  high 
heat,  union  is  effected,  the  whole  passing  into  a  fluid 
state.  Generally  the  percentage  of  basic  in  the  refuse 
is  not  sufficient  in  its  action  on  the  acid  matter  to 
reduce  it  to  such  a  fluid  state  that  it  will  flow  freely, 
or  properly  extract  all  extraneous  matter  from  the  ore. 
To  remedy  this  defect,  limestone  or  other  flux  is  gen- 
erally added  to  all  charges  of  ore  going  to  a  furnace. 
While  the  lime,  etc.,  assists  in  fluxing  the  refuse  to 
the  state  of  fluidity  required,  it  also  affects  the  quality 
of  the  iron  produced  as  described  in  pages  53  and  54. 

The  grade  of  iron  which  is  to  come  from  a  furnace 
can  generally  be  foretold  by  the  nature  of  the  slag 
tapped  or  flushed  before  the  iron  is  tapped.  If  a  lump 
of  solid  slag,  when  broken,  presents  a  black  color, 
very  dense  in  its  composition,  it  is  generally  supposed 
to  denote  the  production  of  iron  very  low  in  silicon  and 
high  in  sulphur,  with  high  iron  in  the  slag.  If  slag  is 
of  a  light  or  gray  color  and  its  fracture  presents  a  porous 


64  METALLURGY    OF    CAST    IRON. 

composition,  it  is  generally  an  indication  of  a  produc- 
tion of  iron  which  will  be  well  up  in  silicon  and  low  in 
sulphur,  with  low  iron  in  the  slag.  Degrees  in  color 
and  solidity  of  the  slag  between  the  two  extremes  may 
vary  according  to  the  difference  found  in  the  grade  of 
the  iron.  Foundry  irons  generally  produce  a  slag 
more  silicious  or  * '  stony  ' '  than  Bessemer  irons.  The 
use  of  high  manganese  or  manganiferous  ores  gener- 
ally produces  either  a  green  or  brown  slag.  A  green, 
glassy  slag,  from  such  ores,  indicates  that  the  furnace 
is  working  well,  but  a  brown  slag  denotes  the  reverse. 
These  grades  of  slag  are  generally  produced  in  the 
making  of  spiegeleisen  and  high  manganese  iron. 

The  slag  called  "  scouring  cinder"  is  generally  the 
worst  slag  which  comes  from  a  furnace.  It  is  of  a 
reddish  brown  color  and  is  chiefly  caused  by  a  slip  or 
some  bad  working  of  a  furnace,  causing  ore  to  pass 
down  to  the  fusion  zone  in  an  unreduced  state.  This 
class  of  slag  is  very  cutting  to  the  lower  lining  of  a 
furnace,  owing  to  its  containing  so  much  oxide  of  iron 
and  being  very  basic,  a  combination  most  effective  in 
dissolving  the  silica  in  the  bricks  forming  the  lining. 
Some  furnacemen  are  having  their  slags  analyzed  at 
every  cast,  as  a  guide  in  regulating  their  furnace. 
This  proves  very  satisfactory  in  assuring  a  furnaceman 
as  to  the  character  of  the  iron  he  may  expect,  or 
whether  any  changes  are  taking  place  which  might 
call  for  prompt  attention  in  making  alterations  in  the 
manner  of  charging  or  working  of  his  furnace.  Some 
expert  furnacemen  can  greatly  vary  the  grain  of  an 
iron  by  methods  of  fluxing  or,  in  other  words,  cause 
like  percentages  of  silicon,  sulphur,  and  carbon  to 
make  some  casts  open-grained  and  others  close-grained 
iron.  This  shows  still  further  why  the  appearance  of 
fractures  in  pig  iron  is  so  often  deceptive. 


FLUXING    AND    SLAGGING    OUT    FURNACES. 


To  afford  some  knowledge  of  the  chemical  relation 

which  slags  bear  to  the  iron  produced,  the  analyses  in 
Tables  n,  12,  and  13,  obtained  by  the  author,  are 
presented : 

TABLE    II  —  ANALYSIS    OF    FOUNDRY    IRON. 


Silicon. 

Sulphur. 

Manganese. 

Phosphorus. 

2.09 

.013 

•25 

.769 

TABLE    12  —  ANALYSIS    OF    SLAG. 


Silica. 

Alumina. 

Lime. 

Manganese. 

Magnesia. 

Iron. 

Total. 

33-o8 

19-74 

44-74 

.11 

1.44 

.40 

99-51 

Table  13  is  slag  selected  from  the  compilations  of 
different  authors  to  present  a  knowledge  of  the  char- 
acter of  slag  produced  from  different  ores  and  classes 
of  fuel.  The  first  and  second  columns  are  slags  pro- 
duced from  raw  coal  smelting  at  Dowlais,  Wales, 
presented  by  Riley.  The  first  column  is  a  slag  from 
gray  iron  and  the  second  from  white  iron.  The  third 
column  is  a  slag  from  coke  with  Cleveland  ores  making 
gray  iron,  by  Bell.  The  fourth  is  from  anthracite, 
making  gray  forge  iron,  at  Bloomington,  N.  J.,  and 
the  fifth  is  from  charcoal  iron  made  at  Josberg, 
Sweden,  by  Sjogren: 

TABLE    13  —  ANALYSES   OF   BLAST    FURNACE    SLAGS    FROM    DIFFERENT 
ORES    AND    FUELS. 


i 

2 

3 

4 

5 

Silica  

38.48 

43-O7 

27.68 

42.  17 

61.06 

Alumina  

IS-  M 

M.8s 

22.28 

r-,8 

Lime 

32   82 

28   02 

19  81 

Protoxide  of  Iron  

O.76 

2  53 

0.80 

1.28 

•*.  2Q 

Manganese 

1.62 

I  •  VI 

0.27 

2    6T 

Magnesia  

7-44 

5.87 

7.27 

8.31 

7.12 

Sulphide  of  Calcium  

2.22 

1  .90 

2.OO 

0.64 

Alkalis  

1.92 

I  84 

Phosphoric  Acid  

o.  15 

100.54 

100.35 

IOO-35 

99-23 

99.29 

66  METALLURGY    OF    CAST    IRON. 

The  percentage  of  silica  slag  contains,  sometimes  as 
high  as  60.00,  as  seen  in  Table  13,  shows  us  ways  in 
which  silicon  can  be  carried  off  or  reduced  in  smelting 
or  remelting  iron.  The  weight  of  slag  produced  is 
dependent  upon  the  character  of  the  ore,  fuel,  and  flux 
used.  The  furnace  can  produce  a  greater  weight  of 
slag  than  iron,  but,  as  a  rule,  600  to  1,000  pounds  of 
slag  are  made  to  the  ton  of  iron.  The  richer  the  ore, 
the  less  slag  in  the  normal  working  of  a  furnace.  The 
slag  created  at  a  furnace  must  be  disposed  of.  We 
find  machinery  utilized  in  this  work,  as  in  other  manipu- 
lations of  furnace  practice.  Some  have  it  conveyed 
in  large  receptacles,  which  are  hauled  by  power  to  cars 
or  dumping  ground.  When  overturned,  they  release 
the  slag  in  a  molten  form,  or  solidified  state.  Another 
plan  is  to  let  it  run  from  the  spout  Y,  Fig.  18,  page  90, 
to  furrows  in  the  ground,  which  may  be  run  for  a 
length  of  two  or  three  hundred  feet,  often  covering  an 
acre  of  ground.  This  slag  is  pulled  out  of  its  furrows 
by  hooks  in  the  hands  of  men  before  it  has  thoroughly 
solidified.  In  removing  the  slag  from  the  ground  it  is 
shoveled  into  carts  and  teamed  to  the  dump,  or  thrown 
on  cars  to  be  transported  and  used  for  railroad  ballast, 
or  for  making  roadways.  Then  again,  the  slag  is  run 
into  a  deep  pit,  after  being  granulated  by  a  stream  of 
water  issuing  from  a  pipe  in  the  trough,  which  strikes 
the  slag  as  it  leaves  the  trough  to  drop  into  the  pit. 
This  granulated  slag  is  hoisted  by  a  steam  shovel  and 
dumped  into  cars,  doing  away  with  much  hand  labor. 
This  plan  is  used  at  the  Alice  Furnace,  Sharpsville, 
Pa.,  and  Ella  Furnace  at  West  Middlesex,  Pa.,  after 
plans  designed  by  Mr.  E.  H.  Williams,  the  general 
manager.  The  pit  used  is  about  twenty  feet  square  by 


FLUXING    AND    SLAGGING    OUT    FURNACES.  67 

twenty  feet  deep,  and  all  the  slag  made  by  the  furnace 
is  dumped  by  the  steam  shovel  into  cars  and  used  by 
some  railroads  as  ballast,  and  filling'  up  dumps. 

Mineral  wool  is  made  from  slag  by  remelting  fur- 
nace slag  in  a  cupola,  under  patents  obtained  by  Wood 
Brothers,  of  Wheatland,  Pa.  The  process  consists  of 
charging  the  slag  in  connection  with  coke  after  the 
plan  of  melting  iron.  As  the  slag  flows  out  it  is  met 
at  the  outlet  of  the  slag-hole  by  three  flat  streams  of 
steam,  which  divide  its  particles  into  threads  of  mineral 
wool  and  blow  the  same  into  a  large  building  about 
one  hundred  feet  long  and  thirty  feet  wide,  pre- 
pared for  its  reception.  Variations  in  the  character  of 
slags  create  different  grades  of  wool,  which  is  sorted 
and  packed  according  to  its  commercial  value.  The 
wool  may  often  be  of  such  a  coarse,  poor  quality  as  to 
be  unfit  for  commercial  purposes.  There  is  always  a 
difference  in  the  density  of  the  wool  at  every  cast. 
The  lightest  is  deposited  or  blown  farthest  from  the 
cupola  and  the  heaviest  grade  nearest  to  the  cupola. 
The  wool  is  chiefly  used  as  a  non-conductor  of  fire, 
packed  between  the  walls  and  floor  spaces  of  fire-proof 
buildings,  etc.  This  mineral  wool  resembles  in  char- 
acter that  which  the  founder  finds  coming  from  cupolas 
which  are  slagged  out. 

For  every  tap  of  iron  made  from  a  furnace,  there 
are  generally  two  taps  for  slag.  This  is  termed  '  *  flush- 
ing a  furnace."  In  the  furnace  shown,  Fig.  6,  page 
34,  the  number  of  taps  for  iron  during  twenty-four 
hours  generally  ranges  from  four  to  five.  In  about 
the  middle  of  every  tap  the  furnace  is  ' l  flushed  ' '  and 
then  again  about  twenty  minutes  before  tapping  for 
iron.  The  old  way  of  tapping  to  flush  a  furnace  is 


68  METALLURGY    OF    CAST    IRON. 

simply  by  having  a  hole  in  the  lining  through  to  the 
inside  of  the  furnace,  and  after  the  same  is  tapped  to 
plug  it  with  clay,  on  the  same  principle  generally 
followed  in  tapping  a  slag-hole  in  cupola  work.  The 
modern  plan  for  making  and  operating  a  flushing-hole 
is  that  shown  in  Figs.  18  and  19,  pages  90  and  93.  At 
N  is  a  bronze  casting  into  which  is  inserted  what  is 
termed  a  "  monkey  tuyere,"  P,  both  of  which  are  kept 
cool  by  a  flow  of  water  passing  through  them.  In  tap- 
ping a  slag-hole  to  flush  a  furnace  the  projection  H  is 
slightly  jarred  by  means  of  a  sledge  which  loosens  the 
stopper  R.  After  this  has  been  removed,  as  shown 
by  A,  Fig.  18,  a  steel  pointed  bar  is  then  used  to  cut 
through  the  inch  or  two  of  chilled  slag,  which  has 
generally  been  formed  in  front  of  the  plug  F.  This 
chilled  slag  is  generally  removed  with  ease,  permitting 
the  cinder  to  flow  out.  The  time  generally  taken  for 
the  slag  to  be  all  flushed  out  ranges  from  five  to  seven 
minutes.  It  is  not  long  after  the  slag  has  commenced 
to  run  before  the  blast  makes  its  appearance,  blowing 
gas  and  sparks  of  cinder  for  from  twenty  to  thirty  feet 
from  the  flushing-hole.  As  soon  as  the  flushing  is 
completed,  the  iron  plug  stopper  R  is  quickly  thrust 
into  the  hole,  which  at  once  chills  the  slag  around  it, 
and  stops  the  leakage  of  blast.  The  stopper  R  is  a 
wrought  iron  bar  with  a  cast  iron  cone  cast  on  the  rod 
which  forms  the  plug  as  shown.  The  difference 
between  this  method  of  tapping  a  flushing-hole  and 
the  old  plan  used  is  simply  in  the  convenience,  and 
the  use  of  clay  is  avoided.  The  iron  and  slag-holes  of 
a  furnace  are  sometimes  lowered  or  raised  from  their 
original  positions  by  reason  of  a  furnace  filling  up  with 
chilled  iron,  but  if  this  can  be  avoided  by  tapping  the 


FLUXING    AND    SLAGGING    OUT    FURNACES.  69 

iron,  as  well  as  the  cinders,  out  of  the  slag-holes,  as 
described  in  the  middle  of  the  chapter,  it  is  often  done 
in  preference  to  changing  the  position  of  the  iron  and 
slag-hole,  as  above  described.  Any  one  desiring 
further  information  on  fluxing  or  slagging  in  its  rela- 
tion to  cupola  work  is  referred  to  * '  American  Foundry 
Practice,"  page  331,  and  the  "  Moulder's  Text-Book," 
page  310. 


CHAPTER  IX. 

COLD  AND  HOT  BLAST  VS.  COMBUSTION. 

There  are  four  kinds  of  blast.  The  first  is  called 
"cold  blast,"  the  second  "warm  blast,"  the  third 
"hot  blast,"  and  the  fourth  "  superheated  blast." 
Cold  blast  is  generally  employed  by  founders  in 
remelting  metals  in  a  cupola,  air,  or  crucible  furnace ; 
also  by  charcoal  blast  furnace  operators.  Warm,  hot, 
and  superheated  blasts  are  generally  used  for  smelting 
ores  to  produce  iron  or  other  metals.  Warm  blast  is 
air  heated  from  250  to  400  degrees  F.  Blast  heated 
above  1,100  degrees  F.  is  generally  termed  super- 
heated blast,  and  if  the  temperature  ranges  from  700 
to  1,100  degrees  F.  it  is  generally  known  as  hot  blast. 
There  are  two  properties  in  the  blast,  the  first  being 
physical  and  the  second  chemical.  With  a  temperature 
of  60  degrees  F.  and  the  barometer  at  30  inches,  air 
weighs  about  one-eight-hundred-fifteenth  part  as  much 
as  water.*  The  weight  of  blast  passing  through  a 
furnace  in  smelting  ore  to  produce  iron  is  greater  than 
the  combined  weight  of  the  fuels,  ore,  and  flux 
charged.  Blast  or  air  contains  chiefly  a  mixture  of 
two  gases,  nitrogen  and  oxygen,  which  is  recorded 
by  volume  and  weight  in  the  following  Table  14: 

*  Table  131,  page  591,  at  the  close  of  this  work,  gives  the  dif- 
ference in  value  of  degrees  between  Fahrenheit  and  Centigrade 
methods. 


COLD    AND    HOT    BLAST    VS.     COMBUSTION.  7 1 

TABLE    14. 


* 

Volume^ 

Weight. 

Nitrojren 

79'  T9 

76.99 

Oxygen  

20.81 

23.01 

100.00 

IOO.OO 

As  the  blast  is  forced  into  a  furnace  or  cupola,  the 

oxygen  combines  with  the  carbon  of  the  fuel  and 
produces  carbonic  acid  gas,  which  is  two  atoms  of 
oxygen  to ,  one  of  carbon.  This  gas,  in  passing  up- 
ward, takes  up  more  carbon  and  is  gradually  converted 
into  carbonic  oxide,  a  gas  which  soon  gains  supremacy 
in  lowering  the  high  temperature  necessary  to  liquid- 
ize ores  or  metals.  By  considering  that  a  state  of 
carbonic  acid  is  necessary  to  liquidize,  and  that  car- 
bon-oxide alone  will  not  heat  metals  to  a  red  hot  color, 
we  are  in  a  position  to  fairly  comprehend  the  differ- 
ence in  degrees  of  temperature  which  ascending  gases 
must  have  in  reducing  ores  in  a  furnace  or  melting 
iron  in  a  cupola.  It  is  said  that  one  unit  of  carbon 
passing  to  the  state  of  carbonic  oxide  only  yields  2400 
heat  units  centigrade,  but  when  it  becomes  carbonic 
acid,  5,600  additional  heat  units  are  evolved,  further 
illustrating  the  difference  in  temperature  which  the 
two  states  of  carbon  can  create. 

The  existence  of  carbonic  oxide  is  essential  in  the 
blast  furnace  for  the  reduction  of  ores  to  produce  iron, 
but  not  in  remelting  iron.  In  the  cupola  the  less  car- 
bonic oxide  gas,  the  greater  the  economy,  and,  to 
decrease  this  gas,  upper  tuyeres  are  sometimes  utilized. 
These  supply  additional  oxygen  to  the  escaping  car- 
bon and  convert  it  back  more  to  carbonic  acid  gas  and 


72  METALLURGY    OF    CAST    IRON. 

give  greater  heat  in  the  cupola.  This  is  so  effective 
that  where  upper  tuyeres  are  not  used,  the  escape  of 
carbonic  oxide  gas  may  often  be  so  great  that  when  it 
reaches  the  charging  door  and  obtains  oxygen  from 
the  air,  it  often  creates  such  a  combustion  as  to  send  a 
flame  many  feet  above  the  top  of  the  stack,  causing 
much  loss  of  heat. 

The  following  Tables  15,  16,  and  17  show  the  amount 
of  heat  absorbed  in  smelting  and  that  lost  by  radiation 
and  in  gases,  according  to  Sir  Lowthian  Bell's  esti- 
mate, expressed  in  hundredth-weight  heat  units  per 
ton  of  iron  produced : 

TABLE    15. — HEAT    PRODUCTION. 

Oxidation  of  carbon 81,536  units 

Contributed  by  blast u,9l9     " 

93,455 

TABLE   16. — HEAT   ABSORPTION. 

Evaporation  of  water  in  coke 312  units 

Reduction  of  iron 33,i°8 

Carbon  impregnation M43 

Expulsion  of  CO  2  from  limestone 5,054 

Decomposition  of  CO  2 5,248 

Decomposition  of  water  in  blast 2,720 

Phosphorus,  silicon  and  sulphur  reduced 4,174 

Fusion  of  pig  iron 6,6co 

Fusion  of  slag 16,720 

75,376 
TABLE   17. — HEAT   LOSS. 

Transmission  through  walls  of  furnace 3>658  units 

Carried  off  in  tuyere  water 1,818 

Carried  off  in  gases 8,860 

Expansion  of  blast,  loss  of  hearth,  etc 3.743 

18,079 


93,455 


By  increasing  the  height  of  furnaces  from  seventy 
to  one  hundred  feet,  as  practiced  at  the  present  day, 


COLD    AND    HOT    BLAST    VS.    COMBUSTION.  73 

much  more  heat  is  utilized  than  formerly  when  fur- 
naces were  about  forty  to  fifty  feet  high.  This  practice 
has  greatly  assisted  furnaces  in  achieving  their  present 
large  output  and  economy  in  making  iron.  This 
experience  is  one  which  the  founder  has  also  found 
advisable  to  follow  in  the  construction  of  cupolas,  as 
they  are  made  to-day  from  four  to  twenty  feet  higher 
than  they  were  fifteen  years  ago.  The  height  now 
generally  followed  is  about  ten  to  sixteen  feet  from  the 
bottom  plate  to  the  lower  level  of  the  charging  door, 
whereas  it  used  to  be  only  from  six  to  nine  feet.  The 
Carnegie  Steel  Co.  has  cupolas  as  high  as  thirty  feet  to 
the  charging  ring. 


CHAPTER  X. 

EFFECTS  OF    BLAST  TEMPERATURES  IN 
DRIVING  FURNACES. 

Hot  blast  is  claimed  to  have  been  first  introduced 

by  Mr.  James  Beaumont  in  Scotland  in  1825.  Up  to 
this  time  cold  blast  only  had  been  used.  The  use  of 
hot  blast  has  increased  in  temperatures  from  100  to 
1,500  degrees  and  higher.  Every  increase  in  tempera- 
ture in  blast  was  found  to  effect  more  or  less  of  a 
saving  in  fuel  and  improve  the  working  of  a  furnace 
up  to  1,700  degrees;  over  this  it  has  not  proved 
economical.  When  only  100  degrees  was  used  it 
proved  to  be  an  advantage  over  the  cold  blast.  Then 
200  degrees  was  used,  showing  better  results  than  100 
degrees,  followed  by  300  and  400  degrees,  and  upward 
until  a  temperature  of  1,000  degrees  was  obtained,  which 
was  as  high  as  iron  stoves  or  pipes  would  stand  the  heat 
without  being  rapidly  burned  away.  The  knowledge 
that  every  increase  in  temperature  had  proved  benefi- 
cial gave  confidence  that  a  higher  temperature  than 
1,000  degrees  would  prove  still  more  economical,  but 
in  order  to  utilize  a  higher  heat  than  1,000  degrees, 
some  other  plan  than  "  iron  stoves  "  had  to  be  devised. 
This  improvement  was  not  long  in  making  its  appear- 
ance. Different  designs  of  stoves  having  all -brick  flues 
which  could  not  be  damaged  to  any  radical  degree 
were  introduced  with  great  success,  and  the  tempera- 


EFFECTS    OF    BLAST    TEMPERATURES.  75 

ture  of  the  blast  was  soon  raised  by  degrees  until 
1,500  to  i, 600  degrees  were  often  utilized  with  benefit 
where  a  furnace  had  ' '  chilled  "  or  * '  got  off  " ;  but  the 
general  practice  of  high  temperature  of  blast  in  the 
normal  working  of  a  furnace  is  not  to  exceed  1,300 
degrees,  being  kept  at  1,100  to  1,200  degrees  with 
brick  stoves  and  900  to  1,000  degrees  with  iron  stoves. 
When  a  furnace  is  working  well,  any  increase  over 
1,200  degrees  in  the  temperature  of  the  blast  is 
claimed  by  many  to  be  more  injurious  in  its  results  on 
the  stock  than  beneficial  in  assisting  a  furnace  to  pro- 
duce a  good  yield  of  iron,  or  ' '  drive  well. ' '  The 
reason  that  high  degrees  of  heat  in  the  blast  will  not 
cause  the  desirable  and  economical  reduction  of  ore 
in  the  furnace,  that  high  heat  derived  from  the  fuel 
will,  is  a  phenomenon  which  all  seem  at  a  loss  to 
understand.  Experience  has  demonstrated  that  a 
temperature  between  1,000  and  1,200  degrees  is  the 
most  desirable  to  maintain.  The  temperature  of  the 
blast  may  be  raised  from  600  to  800  degrees  with 
but  little  improvement,  but  let  this  200  degrees  in- 
crease be  added  to  1,000  degrees  and  the  benefit 
derived  is  extraordinarily  greater  than  any  increase  of 
200  degrees  on  a  lower  temperature.  In  the  normal 
working  of  a  furnace  the  best  results  are  obtained 
with  a  temperature  of  blast  ranging  between  1,000  and 
1,200  degrees  F. 

By  reason  of  utilizing  the  waste  gases  of  a  furnace 
to  heat  cold  blast,  blast  furnace  practice  excels  all 
other  industries  in  obtaining  the  greatest  efficiency 
from  fuel,  as  about  75  per  cent  of  the  heat  generated 
from  the  solid  fuel  is  utilized.  This  is  attained  where 
one  ton  of  coke  will  produce  one  ton  of  iron ;  and  Sir 


76  METALLURGY    OF    CAST    IRON. 

Lowthian  Bell  claims  that  where  this  is  done  all  the 
economy  is  achieved  that  is  practical  to  be  expected  in 
making  iron,  as  long-  as  the  present  fuel  is  used.  To 
note  the  manner  in  which  heat  is  produced,  absorbed 
and  lost,  see  Tables  15,  16  and  17,  page  72. 

Pyrometers.  Various  methods  are  employed  for 
measuring  degrees  of  heat.  Those  of  a  crude  nature 
consist,  for  example,  in  using  dry  sticks  of  wood, 
which  when  inserted  in  hot  air  take  fire,  indicating  a 
temperature  of  about  650  degrees  F.  Again,  sticks  of 
zinc,  if  melted,  indicate  about  750  degrees.  To  obtain 
a  record  of  higher  temperatures  in  a  more  accurate 
manner,  many  different  kinds  of  instruments  have 
been  devised  and  in  recent  years  have  been  largely 
adopted.  A  pyrometer  recently  designed  and  patented 
by  Mr.  E.  A.  Uehling,  of  Birmingham,  Ala.,  in  which 
the  expansion  and  contraction  of  air  between  two 
small  apertures  is  the  principle  used  to  denote  tem- 
perature, is  claimed  to  be  giving  excellent  satisfaction. 
It  is  being  largely  adopted  by  blast  furnacemen  to 
record  for  them  any  variations  in  the  temperatures  of 
the  hot  blast  or  escaping  gases,  and  enables  them  to 
regulate  the  workings  of  a  furnace  so  as  to  give  a 
greater  output  and  produce  ~a  more  uniform  product 
than  heretofore. 

The  question  of  temperatures  in  driving  a  furnace  fast 
or  slow  is  one  of  interest.  It  will  appear  strange  to 
the  founder,  as  well  as  to  others,  that  a  furnace  can  be 
got  so  "  hot  "  as  to  retard  the  speed  of  making  iron, 
and  also  may  result  in  * '  scaffolding ; ' '  nevertheless 
there  is  a  limit  to  attaining  temperatures  best  calcu- 
lated to  drive  a  furnace  to  its  utmost,  which  means  ob- 
taining the  largest  tonnage  possible  in  making  iron. 


EFFECTS    OF    BLAST    TEMPERATURES.  77 

After  this  limit  is  reached,  it  would  seem  that  too 
great  a  body  of  the  ore  was  suddenly  brought  to  such 
a  swollen,  gummy  state,  as  to  retard  the  proper  ascent 
of  the  blast  and  gases.  The  first  factor  to  give  notice 
that  a  furnace  is  getting  ' '  hot  "  is  an  increase  in  the 
temperature  of  the  gases  and  the  refusal  of  the  stock  to 
descend  as  rapidly  as  when  the  furnace  is  working  in 
a  normal  condition.  To  retard  the  increase  of  heat  or 
lower  the  temperatures  to  the  best  point,  it  has  been 
found  that  increasing  the  blast  pressure  would  often 
bring  a  ' 4  hot  furnace  ' '  back  to  its  normal  working. 
By  this  method  a  greater  volume  of  blast  is  admitted, 
which  having  a  lower  temperature  than  the  incandes- 
cent stock  in  the  furnace,  naturally  cools  it  down. 
Then,  again,  a  plan  is  now  largely  adopted  in  having 
arrangements  made  so  that  cold  blast  can  be  turned  on 
at  a  moment's  notice.  This  " brings  a  furnace  'round" 
more  quickly  and  in  a  much  better  manner  than  by 
increasing  the  pressure  of  the  regular  blast  which,  it 
should  be  understood,  will  have  its  temperatures  low- 
ered as  much  as  is  practical  before  being  admitted. 
It  is  chiefly  with  brick  hot-blast  stoves  that  arrange- 
ments are  provided  for  admitting  cold  blast  to  cool  off 
a  furnace,  as  these  carry  higher  temperatures  of  blast 
than  iron  hot-blast  stoves,  as  can  be  seen  by  referring 
to  Chapter  XI.  The  causes  leading  to  "hot"  fur- 
naces can  be  traced  to  excess  of  fuel,  often  brought 
about  by  using  larger  percentages  than  ordinary,  which 
may  be  called  for  by  reason  of  having  to  use  small,  or 
what  is  thought  to  be  inferior  coke  or  fuel,  and  again 
in  burdening  a  furnace  with  fuel  in  order  to  raise  the 
silicon  in  the  iron  or  guard  against  *  *  scaffolding  ' '  or 
"slips"  from  the  use  of  fine  ores,  etc.  It  may  also  be 


78  METALLURGY    OF    CAST    IRON. 

caused  by  a  furnace  perfecting  combustion  of  its  own 
accord  to  such  a  point  as  to  overreach  the  best  temper- 
ature for  driving  well.  It  may  be  said  that  brick 
stoves  have  many  advantages  over  iron  stoves  in  per- 
mitting a  furnaceman  to  regulate  the  temperature  of 
his  furnace  so  as  to  drive  it  well  and  increase  or  di- 
minish the  silicon  or  sulphur  in  the  iron,  and  that  a  radi- 
cal change  is  generally  noticed  in  this  direction  when 
cooling  down  a  "  hot  furnace,"  as  by  such  procedure 
the  silicon  is  often  materially  decreased  and  sulphur 
increased. 

Humidity  of  blast.  It  is  generally  conceded  by  ex- 
perienced furnacemen  that  a  furnace  will  work  better 
and  produce  more  iron  in  cold  than  in  hot  weather. 
It  is  said  that  in  June,  July,  and  August  a  furnace 
never  produces  tonnage  to  equal  other  months  in  the 
year.  The  air  is  generally  dryer  in  cool  than  in  warm 
weather,  and  it  is  now  an  accepted  fact  that  the  extra 
humidity  in  the  summer  air  over  that  in  cold  weather  is 
the  cause  of  the  less  tonnage  in  the  summer  months. 
Some  will  think  the  heat  imparted  to  the  blast  would 
drive  out  all  the  moisture,  but  this  is  claimed  to  be 
simply  transformed  into  a  vapor  which  passes  into  the 
furnace  as  steam.  It  has  been  estimated  that  twenty 
tons  of  water  are  often  transferred,  by  the  blast,  to 
the  interior  of  a  furnace  per  day  by  reason  of  the  high 
humidity  of  air  in  summer  months.  Further  com- 
ments on  this  subject  can  be  found  in  Chapters  IX. 
and  XXXIX. 


CHAPTER  XL 

PLANS     AND     METHODS     OF     WORKING 

BRICK  AND  IRON  STOVES  IN  THE 

CREATION  OF  HOT  BLAST. 

A  knowledge  of  methods  used  in  creating1  hot  blast 
at  the  blast  furnace  is  valuable  to  the  founder  and 
moulder,  as  it  presents  good  ideas  for  the  benefit  of 
those  desiring  to  design  appliances  for  the  purpose  of 
creating  warm  or  hot  blast  for  any  purposes.  .  . 

The  terms  "iron  stoves"  and  "brick  stoves"  are  un- 
derstood to  mean,  in  the  case  of  the  former,  that  the 
cold  air  passes  through  iron  pipes,  while  with  the  lat- 
ter, in  being  heated  to  make  hot  blast,  it  passes  through 
flues  or  checkered  work  composed  wholly  of  fire  brick. 

The  iron  stove  is  fast  disappearing  and  being  re- 
placed by  the  brick  stove,  owing  to  the  ability  of  the 
latter  to  create  the  highest  temperatures  in  blast, 
which  allows  iron  to  be  made  more  cheaply  than  where 
a  temperature  no  higher  than  1,100  degrees  F.  can  be 
created,  as  with  iron  stoves.  A  further  reason  for  this 
displacement  is  that  the  brick  stove  is  less  expensive, 
in  matters  pertaining  to  repairs  and  * '  shut-downs, ' '  to 
keep  a  furnace  running  steadily,  also  in  giving  more 
gas  for  use  under  boilers,  etc.  than  iron  stoves. 

The  operations  of  brick  and  iron  stoves  differ  in 
their  methods  of  being  "in  blast."  The  brick  stoves 
generally  go  out  of  blast  every  hour,  whereas  the  iron 


8o 


METALLURGY    OF    CAST    IRON. 


stoves  generally  run  steadily  |. 
for   six  weeks  at  a  stretch,  | 
and    have   been    known   to  j 
run  without  interruption  for  j 
several    months. 
This    difference   in 
their    operation     is 
due  to  this  principle. 
Brick  stoves  now 
in  use  require   the 
cold  air  to  abstract 
heat  from  the  bricks 
comprising  the  flues 
in  the  ovens,  after 
the  combustible  or 
heating  gases  have 
all    been    shut    off, 
and    in    the   "iron 
stoves  ' '   by  reason 
of    the    iron    pipes    „ 
or    flues     through    ' 
which  the  cold 
air  passes,  be- 
ing separated 
from      union 
with  the  gas- 
es; hence  the 
iron  stove  can 
run    steadily, 
whereas     the 
brick    stove 
runs    only   at 
intervals, 


18  Pect 


FIG.     14.— MASSICK    &    CROOKE    PATENT   BRICK    HOT 
BLAST    STOVE. 


METHODS    FOR    WORKING    HOT    BLAST    STOVES. 


8l 


The  short  duration  of  the  brick  stove  being  "in 
blast ' '  is  due  to  the  rapidity  with  which  the  introduc- 
tion of  cold  air  abstracts  heat  from  the  brick  work. 
The  temperature  of  a  brick  stove  decreases  from  100 
to  300  degrees  F.  in  one  hour's  time.  With  the  plan 


FIG.    15. —  IRON    HOT   BLAST    STOVE. 

of  stove  shown  at  Fig.  14  four  stoves  are  required 
to  keep  a  furnace  steadily  in  blast.  Of  the  four  stoves, 
only  one  is  generally  in  blast,  although  two  may  run 
together  for  the  whole  of  one  turn  of  the  stoves.  The 
plan  generally  followed  is  to  "put  on"  the  stove  going 


82  METALLURGY    OF    CAST    IRON. 

in  blast  a  few  minutes  before  the  one  going  out  of 
blast  is  shut  off. 

The  sectional  views  of  iron  and  brick  hot  blast  stoves 
shown  in  Figs.  14  and  15,  respectively,  are  of  stoves  in 
use  within  a  "stone's  throw"  of  the  author's  foundry. 
The  brick  stoves  shown  are  of  the  most  modern  type, 
recently  built,  and  are  said  to  be  giving  excellent  satis- 
faction. Before  these  stoves  were  built,  iron  ones 
were  used  by  the  same  furnace.  The  four  stoves  are 
said  to  have  cost  $40,000,  and  by  their  adoption  the 
owners  were  enabled  to  produce  pig  iron  30  cents  per 
ton  cheaper  than  when  the  iron  stoves  were  used, 
owing  to  the  brick  stoves  causing  the  furnace  to  use 
less  fuel  and  give  a  larger  yield  of  iron,  also  cheaper 
cost  of  repairs  than  those  required  in  iron  stoves.  It 
may  seem  a  small  saving  for  the  investment  of  $40,000. 
When  pig  iron  was  selling  for  from  $30  to  $50  per  ton 
and  the  furnaceman  had  a  margin  of  profit  of  from 
$15  to  $30,  no  one  thought  of  investing  $40,000  just 
to  save  30  cents  per  ton  on  iron  made.  When  $10  to 
$14  per  ton  is  about  all  a  furnaceman  can  get  for  his 
iron,  as  is  now  often  the  case,  a  saving  of  30  cents  per 
ton  is  quite  an  item,  especially  so  if  it  will  permit  one 
furnaceman  underselling  another  and  leave  a  few  cents 
profit  on  his  sales. 

There  are  several  different  types  of  brick  hot  blast 
stoves  now  in  use,  and  it  now  seems  as  if  it  will  be  but 
a  few  years  before  iron  stoves  will  be  almost  wholly 
abandoned,  mainly  because  the  brick  stove  can  make 
iron  more  cheaply  than  the  iron  stove.  A  large  num- 
ber of  furnaces  are  still  using  iron  stoves,  but  as  soon 
as  they  are  worn  out,  or  competition  gets  too  keen,  they 
will  no  doubt  be  largely  replaced  by  the  brick  stoves. 


METHODS    FOR    WORKING    HOT    BLAST    STOVES.  83 

However,  a  description  of  some  of  the  main  features 
and  principles  involved  in  "  iron  stoves  "  cannot  but 
be  of  value  to  many. 

The  plans  and  workings  of  an  iron  stove  should  first 
be  considered.  There  are  several  different  methods 
used  in  piping  an  iron  stove.  Those  commonly  em- 
ployed have  the  inverted  U  and  straight  pipes,  as 
shown  in  Figs.  16  arid  17.  The  inverted  U  pipe  in 
Fig.  1 6  is  the  same  as  those  used  in  the  iron  stove 
illustrated  in  Fig.  15.  This  oven  contains  forty-four 
of  such  pipes,  there  being  eleven  in  a  row  and  four 
rows  in  the  length  of  the  oven.  The  length  and  height 
of  the  oven  are  shown.  The  width  is  twelve  feet.  As 
the  pipes  stand  up  in  the  oven  there  is  about  three 
inches  space  between  them.  The 
knobs  seen  at  T,  Fig.  16,  form 
the  space  of  division  between  them. 
The  section  seen  in  Fig.  17,  page 
84,  is  what  is  called  "  straight 

pipe. ' '  The  division  bar  X  answers  the  same  purpose 
as  making  the  pipes  of  a  U  form,  owing  to  the  rib  X 
running  up  within  about  six  inches  of  the  top  end  of 
the  pipe,  when  erected  in  the  oven.  A  similar  parti- 
tion as  at  X  is  also  in  the  bed  pipe;  this  causes  the 
blast  to  pass  up  one  side  and  come  down  the  other, 
thus  serving  the  same  purpose  as  the  pipe  at  Fig.  16. 
The  straight  pipes  have  the  advantage  of  being  more 
easily  handled  in  taking  them  out  of  an  oven  when 
they  burn  out  or  crack,  as  they  often  do.  The  top  of 
the  oven  is  so  constructed  that  the  plate  can  be  re- 
moved to  permit  bad  pipes  being  hoisted  out  by  means 
of  an  erected  pole  on  the  outside  of  the  oven.  It  is 
far  from  being  an  easy  or  pleasant  job  to  replace  burnt 


84  METALLURGY    OF    CAST    IRON. 

or  worn-out  pipes.  For  this  reason  much  care  is  ex- 
ercised to  prevent  the  temperature  rising  above  1,100 
degrees  in  the  oven. 

There  is  a  plan  used  in  iron  stoves  of  suspending  the 
iron  pipes  from  the  top  of  the  oven  instead  of  letting 
them  rest  with  their  weight  on  the  "bed  pipe,"  as 
shown  in  Fig.  15.  This  plan  prevents  the  iron  pipes 
from  * '  buckling  ' '  or  bending  from  their  own  weight 
when  they  get  red  hot. 

The  usual    plan    adopted    for   heating   cold   air   to 
make  "  hot  blast  "  in  the  iron  stove  will  be  readily  un- 
derstood by  a  study  of  the  design  illustrated  in  Fig. 
15.     The  arrow  seen  at  A,    Fig.    15,   is  the^  point  at 
which  the  cold  air  enters  the  iron  pipes  in  the  hot  blast 
oven.     As  soon  as  the  cold  air  enters  the 
first  "bed  pipe"   E,  it  takes  the  direction 
shown  by  the  arrow  in  the  pipe  B ;   passing 
from  this  to  the  "bed  pipe"  F,  then  travel- 
ing up  the  pipe  D  and  down  into  the  bed 
pipe  H,  continuing  such  a  line  of  travel  through  four  to 
six  more  pipes,  according  to  the  length  of  an  oven,  un- 
til the  blast  reaches  the  outlet  at  K  on  the  right,  from 
which  it  then  enters  the  blast  furnace  as  * '  hot  blast. ' ' 

The  action  of  gases  is  next  to  be  considered.  A  point 
to  be  understood  is  that  of  the  means  employed  for 
heating  the  oven  or  iron  pipes  to  create  ' '  hot  blast. ' ' 
This  is  accomplished  through  the  use  of  waste  gases, 
which  escape  at  the  top  of  a  furnace,  and  are  passed 
down  through  the  ' '  down-comer, ' '  seen  on  the 
right,  to  a  flue  N  N,  and  then  rising  into  the  ovens 
through  the  openings  M  and  P,  until  they  reach  the 
combustion  chamber  R,  where  they  ignite  as  soon  as 
they  reach  the  point  S,  by  reason  of  the  gas  being  met 


METHODS    FOR    WORKING    HOT    BLAST    STOVES.  85 

by  a  fresh  supply  of  oxygen  or  air  and  the  heat  of  the 
oven,  The  chimney  seen  on  top  of  the  ovens  at  W 
creates  a  draft  and  permits  the  smoke  or  dead  gas  to 
escape.  All  the  space  about  the  pipes  B  and  D  is 
called  the  * '  combtistion  chamber, ' '  and  when  the  gas 
is  burning  in  the  oven  this  space  area  is  filled  with  a 
flaming  gas  fire. 

Should  the  furnace  go  out  of  blast  for  any  reason  to 
exceed  two  hours,  the  oven  will  generally  cool  down  to 
such  a  degree  as  to  be  very  liable  to  cause  an  explo- 
sion when  the  gas  begins  to  enter.  Again,  the  oven 
being  cold,  could  not  heat  the  blast  at  the  start  to  any 
effective  degree,  and  hence  less  iron  would  be  pro- 
duced, with  a  chance  of  also  promoting  "  chilling  "  in 
the  furnace.  To  prevent  or  guard  against  such  ill  re- 
sults, a  wood  or  coal  fire  is  generally  built  in  flues  P 
by  opening  the  doors  V.  By  such  a  plan  the  heat  of 
the  oven  can  be  maintained  to  700  to  800  degrees.  It 
is  not  infrequent  that  items  are  noticed  in  the  trade 
and  daily  papers  speaking  of  some  furnace  having  had 
a  gas  explosion.  A  cold  oven  is  often  the  cause,  and 
furnacemen  watch  this  point  very  closely.  Not  only 
is  it  necessary  that  the  ovens  be  hot  when  the  gas  from 
the  ovens  first  enters  them,  but  it  is  also  desirable  that 
a  flame  be  burning  in  the  oven  to  insure  the  gas  ignit- 
ing. Some  furnacemen  will  take  no  chances  in  this  re- 
spect. If  they  shut  down  but  for  half  an  hour  they  will 
either  have  some  dry  wood  or  a  few  lumps  of  soft  coal 
placed  in  the  oven  so  as  to  insure  a  flame  therein  when 
the  furnace  begins  to  send  its  gas  down  the  "  down- 
comer. "  A  gas  explosion  can  cause  great  damage, 
and  the  wise  take  no  chances  or  risk  with  it. 

The  color  of  the  gases  escaping  from  the  chimney 


86  METALLURGY  OF  CAST  IRON. 

W,  and  also  of  the  flame  in  the  ovens,  affords  an  experi- 
enced furnaceman  much  knowledge  of  the  condition 
of  a  furnace  or  what  results  may  be  expected  in  its 
workings.  In  this  respect,  also  in  regard  to  explo- 
sions, the  same  is  to  be  said  of  a  brick  stove  as  of  the 
iron  one,  and  a  close  watch  is  generally  kept  of  the  color 
and  action  of  the  gases.  The  gas,  as  it  escapes  from 
the  top  of  a  furnace  in  its  passage  downward  to  the 
iron  or  brick  oven,  is  chiefly  in  the  form  of  carbonic 
oxide  and  may  often  not  have  a  temperature  of  300  de- 
grees of  heat,  although  it  generally  ranges  from  400 
to  500  degrees  as  it  passes  through  the  "down-com- 
er "  to  the  ovens.  This  form  of  gas  is  an  explosive, 
requiring  air  to  make  it  combustible.  This  element  it 
receives  after  it  has  entered  the  ovens,  the  air  being 
drawn  from  outer  channels  or  flues  in  the  brick  work 
of  the  iron  stoves,  as  at  H  and  F  in  the  brick  stove ; 
this  action  creates  the  flame  in  the  ovens  just  cited, 
which  then  raises  the  temperature  to  the  degrees  above 
noted.  If  the  gas  were  allowed  to  pass  into  the  oven 
in  the  state  in  which  it  comes  from  the  top  of  a  furnace 
through  the  "down-comer"  without  receiving  a  suffi- 
cient supply  of  air,  the  gas  would  be  of  little  value  in 
raising  the  temperature  of  the  blast  confined  in  the 
pipes  on  its  passage  to  the  furnace. 

The  plans  and  working  of  a  brick  stove  are  as  fol- 
lows: The  line  of  the  arrows  seen  in  Fig.  14  displays 
the  various  channels  through  which  the  cold  blast 
travels  after  entering  the  brick  stove  at  E,  seen  at  the 
end  of  the  cold  blast  inlet  pipe.  The  direction  of  the 
cold  blast  in  being  heated  is  directly  opposite  to  that 
taken  by  the  gas  coming  from  the  furnace  to  heat  up 
the  walls  and  various  channels  and  checkered  brick 


METHODS    FOR    WORKING    HOT    BLAST    STOVES.  87 

work  in  the  stove.  This  is  the  plan  followed  in  all 
modern  brick  stoves.  The  gas  in  leaving  the  * '  down- 
comer  ' '  is  carried  through  gas  mains  to  V,  where  it 
passes  the  gas  valve  at  X  and  enters  the  furnace  at 
H.  Before  the  gas  is  turned  on,  the  cap  K,  which 
closes  the  gas  inlet  while  the  blast  is  passing  through 
the  stove  to  be  heated,  is  removed  and  the  gas  valve 
slid  up  so  that  the  end  of  the  pipe  at  X  is  about  even 
with  the  face  of  the  gas  inlet.  The  pipe  X,  being 
smaller  in  diameter  than  the  hole  of  the  gas  inlet  at 
H,  permits  air  to  unite  with  the  gas  as  it  enters  the 
stove,  thereby  causing  combustion  or  ignition  of  the 
gas  at  the  entrance  before  it  passes  to  the  combustion 
chamber,  where  it  receives  more  air  by  means  of  the 
air  inlet  T,  which  is  opened  when  the  gas  is  turned  on. 
At  T,  W  and  D  are  seen  points  at  which  valves  are  ar- 
ranged for  opening  or  closing  the  passage  of  air  or 
gas,  as  the  case  may  be.  When  the  gas  is  being  turned 
on,  the  valve  D  is  opened.  As  now  shown,  it  is  closed 
so  as  to  prevent  any  gas  escaping  up  the  chimney  P. 
Before  the  gas  is  turned  on,  the  valve  D  is  opened  so 
as  to  create  draft  and  permit  the  dead  gas  and  flames 
to  escape  through  the  chimney.  The  valves  T  and  W 
are  closed  when  the  gas  is  on,  as  will  be  evident  to 
any  making  a  study  of  the  plans  shown.  In  a  general 
way  the  blast  is  on  a  stove  for  one  hour  and  the  gas 
for  three.  Three  stoves  are  generally  on  gas  while 
one  is  in  blast,  unless  one  is  being  cleaned  of  the  caked 
flue  dust  which  rapidly  gathers  on  the  combustion 
chambers  for  a  distance  of  about  twenty  feet  in  height, 
and  on  the  bottom  of  the  stoves,  which  have  openings 
as  at  K  and  S  for  getting  at  or  cleaning  out  the  stove, 
or,  if  shut  off,  for  repairs. 


88  METALLURGY    OF    CAST    IRON. 

The  valve  at  T  is  arranged  with  piping,  through 
which  water  runs  in  order  to  protect  the  exposed  parts 
of  the  valve  from  burning  out.  The  valves  W  and  D 
do  not  require  the  presence  of  water,  for  the  reason 
that  when  the  gas  is  on,  the  brick  work  of  the  stove 
absorbs  the  greatest  heat  at  its  bottom,  which  pre- 
vents the  highest  temperature  being  confined  to  the 
upper  part  of  the  stove.  One  stove,  when  a  furnace 
is  working  well,  is  all  that  is  generally  "  in  blast;  " 
but  if  there  should  be  a  "  slip  ' '  to  chill  a  furnace  or 
make  it  work  cold,  two  or  three  stoves  are  often  put  on 
at  one  time  for  a  short  duration  to  assist  in  raising  the 
temperature  in  the  furnace  so  as  to  restore  it  to  its 
normal  condition,  after  which  the  additional  stoves  are 
taken  off  and .  the  work  continued  with  but  one,  as  in 
ordinary  practice. 

The  four  stoves  are  placed  together  as  closely  as  is 
convenient  to  leave  room  for  working  around  them. 
They  cover  an  area  of  ground  about  40x50  feet.  The 
four  stoves  are  connected  by  band  pipes  and  separate 
valves,  so  that  the  cold  blast  coming  from  the  "blow- 
ing tubes  "  and  the  hot  blast  leading  to  the  four  stoves 
come  from  and  lead  into  one  main  pipe.  The  pipes 
which  convey  the  hot  blast  to  the  furnace  are  either 
coated  with  an  asbestos  covering  or  have  their  interior 
lined  with  fire  brick,  the  same  as  is  done  with  the 
'  *  down-comer  ' '  which  carries  the  dead  gas  from  the 
top  of  the  furnace  down  to  the  combustion  chamber 
of  the  hot  blast  stoves  to  protect  them  and  prevent 
loss  of  heat. 


CHAPTER  XII. 

TAPPING-OUT    AND    STOPPING-UP    FUR- 
NACES AND  CUPOLAS. 

It  has  taken  much  time,  study,  and  experience  to  at- 
tain the  present  perfection  in  controlling  the  output  of 
a  modern  furnace.  The  history  of  blast  furnaces 
shows  many  disasters  in  '  *  breakouts, "  "  boils, ' '  and 
explosions.  When  all  is  working-  well  about  a  furnace 
everything  seems  very  simple  and  as  if  taking  care  of 
itself,  but  it  is  when  all  does  not  go  well  that  one  is 
impressed  with  the  fact  that  furnacing  is  often  more 
like  hades  let  loose  than  a  paradise  of  comfort,  ease, 
and  pleasure.  An  observing  founder  standing  at  a 
distance  watching  a  furnace  being  tapped  might  often 
be  at  a  loss  to  understand  why  a  cupola  cannot  have 
its  * '  breast ' '  stopped  the  same  as  the  * '  notch  "  of  a  fur- 
nace. The  founder  often  has  trouble  with  cupola  tap- 
holes,  which  when  once  started  to  work  badly  will 
often  continue  to  do  so  throughout  the  balance  of  the 
heat.  The  secret  of  the  furnaceman  being  able  to  stop 
a  notch  by  hand  in  the  way  it  is  generally  done,  is 
that  the  metal,  when  all  is  working  well,  is  left  lower 
than  the  notch-hole,  about  as  illustrated  at  the  level  O, 
Fig.  1 8,  page  90.  How  the  metal  goes  down  to  such  a 
low  level  as  shown  is  a  puzzle  to  the  founder  who  has 


9o 


METALLURGY    OF    CAST    IRON. 


J L 


FIG.  1 8. 


never  seen  a  furnace. 
The  tapping-hole  K 
is  generally  made  at 
an  angle  somewhat 
as  shown.  After  the 
metal  has  run  out  all 
it  will  by  force  of 
gravity,  the  blast 
pressure  is  increased 
above  the  ordinary  to 
drive  or  siphon  it  out, 
as  called  by  some,  to 
about  the  level  shown 
at  the  dotted  line  O. 
With  the  weight  of  stock  bearing  down  on  the  molten 
mass  in  a  crucible  and  blast  pressure  of  10  pounds  or 
more  to  the  square  inch,  it  seems  reasonable  to  expect 
the  results  described.  We  know  the  weight  of  stock  and 
pressure  of  blast  exerts  such  a  driving-out  influence; 
from  the  fact  that  when  about  two-thirds  of  the  pig  beds 
are  poured,  the  metal  will  often  almost  stop  running,  at 
which  point  the  blast  pressure  being  increased  a  fourth 
more  metal  will  often  be  forced  out,  and  the  more 
acute  the  angle  of  the  notch,  so  as  to  carry  its  opening 
lower  into  the  crucible,  the  more  metal  to  a  depth  of 
about  15  inches  below  the  level  of  the  bottom  of  the 
iron  trough  can  be  siphoned  out  in  tapping  a  furnace. 
A  question  which  suggests  itself  here  is  the  reason 
for  having  such  a  body  of  metal  below  the  level  of  a 
notch-hole.  The  great  depth  sometimes  attained  is 
not  really  desired,  but  is  ceased  by  the  liquid  mass 
burning  out  the  bottom  brick-work. 

When  "blowing-in"  a  new  furnace,  the  bottom  bed  of 


OF  THE 
* 


TAPPING-OUT  AND  STOPPING-UP  FURNACE 

the  hearth  or  crucible  is  not  much  over  four  inches 
the  level  of  the  notch,  but  continual  running  and  '  '  fast 
driving1  "  of  a  furnace  soon  cut  out  the  bottom  lining, 
so  that  it  is  no  uncommon  result  for  metal  to  burn  the 
bottom  down  two  to  three  feet  below  the  level  of  a 
notch,  as  indicated  by  the  dotted  line  S  in  Fig.  18. 
Furnacemen  claim  it  is  not  until  a  bottom  is  cut  down 
for  a  foot  or  two  that  the  best  output  and  quality 
of  product  can  be  obtained,  and  also  that  a  deep  bed 
is  very  desirable  to  help  maintain  a  uniform  product. 
Often  has  a  furnace  cut  the  bottom  out  to  such  a  depth 
as  to  force  an  opening  for  metal  to  pass  downward 
through  the  ground  or  outward  through  the  sides, 
about  as  is  indicated  by  the  lines  N,  M,  and  H,  Fig.  18. 
The  havoc  such  an  escaping  body  of  metal  can  make, 
if  bursting  out,  as  it  often  does,  into  a  reservoir  of 
water,  which  is  always  more  or  less  deep  around  the 
hearth  of  a  furnace  at  N,  can  be  but  partly  conceived. 
The  mass  of  liquid  metal  in  the  bed  of  a  furnace 
often  weighs  50  to  100  tons.  This  often  solidifies 
and  lies  in  a  furnace  until  it  is  torn  down,  or  the 
hearth  portion  removed  to  permit  its  being  broken  by 
dynamite.  It  has  happened  that,  through  a  furnace 
*  *  getting  off  "  or  working  badly,  the  bed  of  metal  has 
solidified  above  the  level  of  the  notch,  so  that  to  tap 
the  metal  out  of  the  furnace  it  would  have  to  be 
drawn  off  at  the  flushing  or  slag-hole  at  A,  Fig.  18. 
Some  furnaces  have  run  for  a  week  or  two  in  this 
manner  before  they  were  able  to  get  the  solidified 
mass  melted  down,  s-o  as  to  again  draw  metal  from  the 
notch-hole.  A  furnace  in  this  condition  must  be 
tapped  much  oftener  than  when  it  can  be  tapped  at 
the  regular  notch.  It  is  often  surprising  how  rapidly, 


92  METALLURGY    OF    CAST    IRON. 

through  a  furnace  getting  cold,  the  bed  of  metal  in  the 
hearth  will  solidify,  and  then  again  how,  when  a 
furnace  is  working  hot,  it  will  often  cut  out  such  a 
solid  mass  of  iron ;  but  generally,  like  all  workings  of 
mechanical  affairs,  the  evil  is  prolonged  more  than 
the  good  is  hastened,  when  trouble  once  begins. 

Fig.  19  shows  the  effect  of  a  chill  in  a  furnace  caus- 
ing metal  to  solidify  around  and  above  the  notch.  This 
is  one  form,  and  another  form,  instead  of  having  a 
chill  all  around  the  sides  with  liquid  metal  in  the 
middle,  may  have  one  side  solidified  while  its  opposite 
is  in  a  fluid  state.  Solidification  of  such  masses 
generally  occurs  by  reason  of  scaffolding,  cooling  off 
the  furnace,  and  then  letting  a  mass  of  chilled  stock 
slip  down  to  the  tuyeres  or  lower  into  the  hearth. 
There  are  two  forms  of  such  evils  resulting  from  a 
slip,  the  first  being  the  solidification  of  metal  as  above 
described,  and  the  other  what  is  called  a  ' '  lime-set, 
which  is  generally  caused  by  reason  of  a  furnace 
carrying  a  heavy  burden  of  limestone,  and  the  furnace, 
becoming  cold  from  '  *  scaffolding ' '  or  any  other  bad 
working,  chills  the  lime  so  that  it  becomes  too  thick 
to  flush  out,  and  ' '  sets  "  in  a  solid  state  in  the  crucible 
or  at  the  tuyeres. 

Furnacemen  generally  fear  a  ••  lime  set "  more  than 
that  of  molten  metal  solidifying,  for  the  latter  can  be 
melted  away  much  more  readily  than  the  former.  Lime- 
sets  have  been  so  serious  that  furnaces  have  had  to 
"  blow-out"  to  remove  them.  A  method  sometimes 
employed  to  gain  access  through  solidified  iron,  which 
had  closed  up  tuyeres,  or  a  * '  notch, "  so  as  to  prevent 
its  being  tapped,  is  that  illustrated  by  the  hydrogen 
blow-pipe  at  A,  Fig.  19,  page  93.  As  used  in  this  case, 


TAPPING-OUT  AND  STOPPING-UP   FURNACES,   ETC. 


93 


it  is  simply  a  2 -inch 
g  a  s  pipe  leading 
from  the  hot  blast 
pipe  (cold  blast  can 
also  be  used),  into 
which  a  ^-inch  pipe 
D  carries  a  stream 
of  coal  oil.  This  is 
contained  in  a  can 
sufficiently  high  to 
force  the  oil  out  and 
FIG<  J9-  overcome  the  blast 

pressure  at  the  outlet ;  there  it  ignites  by  combination 
of  the  air  and  oil.  Sufficient  heat  is  thus  generated  to 
melt  the  iron  or  enable  it  to  be  knocked  away.  Space 
is  made,  in  this  manner,  which  admits  the  blast  and 
metal  blowing  out  to  further  cut  away  the  solid  iron  to 
a  point  warranting  the  replacing  of  the  notch  for  regular 
working.  In  some  cases  a  coke  or  coal  fire  may  be  en- 
cased in  front  of  the  blow  pipe,  and  the  stock  is  to 
be  cut  away  as  illustrated  by  the  small  lumps  of  fuel 
seen  at  E,  Fig.  19.  The  principle  involved  in  this 
process  is  one  which  may  often  be  practically  applied 
by  the  founder  in  preparing  a  casting  to  be  burned,  by 
bringing  the  point  ot  fracture  to  almost  a  molten  state, 
thereby  saving  labor  of  melting  and  handling  a  large 
quantity  of  molten  metal.  It  may  at  times  also  be 
found  of  value  in  assisting  to  cut  away  heavy  bodies  of 
iron  that  may  be  found  almost  impossible  to  be  other- 
wise manipulated.  In  using  this  device  to  cut  out  a 
notch  of  a  furnace,  great  care  is  exercised,  as  it  may 
cut  through  the  chilled  material  and,  without  warning, 
the  molten  contents  may  burst  out  with  such  force  as 


94  METALLURGY    OF    CAST    IRON. 

to  empty  the  furnace  in  a  few  minutes.  Men  have  been 
struck  by  such  outbursts  and  almost  buried  alive  in  a 
pool  of  metal  before  assistance  could  be  rendered. 

The  process  for  hand=tapping,  when  all  is  working 
well  with  a  notch  of  a  furnace,  is  first  to  take  an  iron 
bar  and  prick  into  the  stopping  clay,  starting  a  hole  as 
seen  at  the  entrance  K,  Fig.  18,  the  "keeper"  being 
careful  to  give  it  the  shape  and  angle  desired.  As  the 
clay  is  loosened,  a  fe -inch  rod,  having  a  flat  lifter  about 
i%  inches  square  on  its  end,  as  seen  in  Fig.  21,  be- 
low, is  used  to  pull  the  loose  clay  up  out  of  the  hole, 

which     is    generally 
made  about  4  inches 
in   diameter    at    the 
FIG- 20>  top,    tapering    down 

.     6v     j  to  2  y2   inches  at  the 

:2di  --  ®          bottom.      Picking  by 

hand  bars  and  lifting 
out  the  loosened  clay 
is  continued  until  the 
FIG  22<  solid   clay   shows  by 

its  red  heat  that  its 

thickness  preventing  the  metal  bursting  out  is  not 
over  3  inches;  then  a  steel  bar  of  about  i#  inches 
diameter  having  a  sharp  point  is  placed  as  shown  in  Fig. 
1 8,  the  upper  end  resting  on  a  piece  of  pig  metal 
thrown  across  the  top  of  the  iron  trough,  as  seen  at  T. 
A  sledge  is  now  used  at  the  end  F,  the  bar  in  the 
meantime  having  its  point  guided  by  hand  so  as  to  cut 
around  the  edge  of  the  hole.  This  is  continued  until 
metal  commences  to  ooze  out  slightly,  when  the  bar  is 
driven  through  the  started  body  of  the  clay  into  the 
metal  seeking  to  force  itself  out.  The  bar  is  then 


TAPPING-OUT  AND  STOPPING-UP  FURNACES,    ETC.        95 

pulled  out,  in  which  movement,  should  any  difficulty  be 
experienced,  a  device  as  seen  at  P,  Fig.  18,  is  used,  which 
by  sledging  on  the  end  of  the  wedge  shown,  backs  the 
bar  out  of  the  notch.  Sometimes,  instead  of  the  device 
shown,  a  stout  ring  will  be  used,  and  by  inserting  the 
wedge  as  shown  a  similar  result  is  insured.  This 
device  is  a  simple  affair,  and  should  suggest  to  many 
founders  a  remedy  for  difficulty  often  experienced  in 
pulling  back  bars  driven  into  the  breast,  tuyeres  or 
slag-holes  of  a  cupola. 

After  a  bar  has  been  removed  from  the  notch,  the 
metal  generally  flows  out  with  a  fair  speed,  but  should 
lumps  of  dross  or  fuel  impede  its  passage,  a  smaller 
bar  than  the  one  used  to  tap  it  is  generally  inserted  in 
the  notch-hole,  and  by  working  it  up  and  down  the 
passage  is  eventually  cleared  so  as  to  permit  the  flow 
desired.  It  is  not  infrequent  that  the  metal  rushes 
out  with  too  great  speed,  often  coming  with  an  unex- 
pected burst,  so  as  to  strike  the  '  *  keeper ' '  with  a 
spreading  sheet  of  rushing  metal  if  he  is  not  continually 
on  his  guard.  After  a  furnace  has  been  tapped  and 
the  iron  commences  to  flow  well,  a  cover  composed  of 
fire  brick  held  in  an  arch  shape  by  a  cast  iron  bracket 
casting  is  swung  by  means  of  an  iron  arm  close  up  to' 
the  furnace  front  at  the  cooler  V,  Fig.  18,  and  let 
rest  on  the  edge  of  the  trough  shown.  Any  space 
between  this  cover  and  the  furnace  shell  is  closed  by 
means  of  sand  being  thrown  around  this  section.  This 
cover  prevents  the  metal  and  slag  from  blowing  up 
against  the  shell  of  the  furnace  and  burning  it  out. 

An  arrangement  which  is  generally  used  at  every 
hand-tap  to  assist  in  lessening  the  force  of  the  stream 
is  a  stopper,  as  seen  in  Fig.  22.  The  end  W,  being 


96  METALLURGY    OF    CAST    IRON. 

held  at  the  mouth  of  the  notch,  can,  if  there  is  not  too 
great  a  force,  often  almost  stop  the  escape  of  metal. 
This  stopper  is  made  by  rolling  a  i^-inch  rod  in  a 
stream  of  slag  as  the  furnace  is  being  flushed  out. 
Should  the  metal  force  itself  out  too  fast  at  any  time 
during  a  tap,  the  blast  is  slackened  or  stopped,  until 
the  metal  has  flowed  off  all  it  will  of  its  own  gravity, 
when  the  blast  is  again  put  on,  and  the  increased 
pressure  then  drives  out  the  metal  and  slag  as  above 
described.  This  end  achieved,  the  blast  is  then  com- 
pletely shut  off  and  the  notch  stopped. 

The  process  of  stopping  the  notch  by  hand  is  pro- 
ceeded with  as  rapidly  as  possible,  in  order  to  prevent 
loss  of  time  in  making  iron.  The  first  thing  done  is 
to  throw  a  sheet-iron  plate  across  the  top  of  the  iron 
trough;  which,  covered  over  with  sand,  protects  the 
men  from  the  heat  of  the  trough,  and  permits  them  to 
come  directly  over  their  work.  The  notch  at  this 
stage  greatly  resembles  a  crater  that  has  died  down 
after  vomiting  its  lava.  Lumps  of  dross  and  fuel  will 
be  found  sticking  to  its  sides,  which  have  been  great- 
ly increased  in  area  from  the  effects  of  the  "blow." 
A  bar  is  used  to  loosen  this  debris,  and  then  an  iron 
scoop  pulls  it  out  of  the  notch-hole.  After  this  debris 
has  been  removed  as  well  as  the  inflowing  slag  will 
permit,  the  bar  is  again  used  to  push  down  into  the 
crucible  any  lumps  which  may  be  sticking  to  the 
sides  of  the  notch,  and  a  bar  of  the  same  shape  as  Fig. 
21,  only  made  of  round  iron,  is  now  used  to  press  down 
into  the  crucible  the  dross  and  slag  which  endeavor  to 
rise  to  fill  the  notch-hole.  This  done,  the  bar  is  hasti- 
ly removed,  and  men  standing  with  two  shovelfuls  of 
clay  toss  it  into  the  notch-hole,  the  clay  is  then  quickly 


TAPPING-OUT   AND  STOPPING-UP  FURNACES,   ETC.          97 

rammed  down  as  far  as  it  is  possible  with  the  rammer 
rod  just  described.  After  as  much  clay  is  pressed 
downward  with  these  rammers  as  is  found  possible, 
then  a  round  stick  about  3  inches  in  diameter  at  the 
small  end  and  3^3  inches  at  the  top,  having  a  ring  to 
prevent  the  sledging  splitting  the  timber  as  seen  at 
Fig.  20,  is  inserted  into  the  notch  and  driven  with  two 
sledges  down  to  the  bottom,  thus  driving  the  dross 
and  clay  back  into  the  crucible,  as  far  as  possible,  to 
make  a  solid  filling  of  clay  in  the  notch  at  its  bot- 
tom. This  method  of  packing  having  been  performed 
half  way  up  the  notch,  the  packing  stick  is  removed, 
the  blast  started,  and  the  balance  of  the  notch  is  then 
rilled  with  clay  packed  with  hand  rammers.  A  stream 
of  hot  blast  is  now  turned  on  the  top  of  the  notch  and 
the  clay  grouting  used  to  coat  the  iron  trough,  so  that 
at  the  next  tap  there  will  be  no  dampness  to  start  a 
"boil." 

The  above  description  is  one  plan  of  hand-stopping  a 
furnace,  but  lately  a  machine  has  been  designed  to  be 
worked  by  steam  forcing  out  a  stopper,*  by  which  a 
furnace  can  be  stopped  at  any  part  of  a  tap  without 
shutting  off  the  blast. 

Many  furnaces  are  now  using  stopping  machines. 
They  prove  valuable  in  many  ways,  especially  in  per- 
mitting a  more  steady  blast,  and  which  gives  a  greater 
output  and  more  uniform  grade  of  metal  and  greatly 
lessens  the  chances  for  scaffolding  due  to  a  more  steady 
heat  being  maintained  in  the  furnace.  It  is  said  that 
all  users  of  these  stopping  machines  praise  them  very 
highly,  and  it  now  looks  as  if  it  would  not  be  long 
before  all  furnaces  would  adopt  them  in  their  practice, 

*  Patented  by  S.  W.  Vaughn,  Johnstown,  Pa. 


98 


METALLURGY    OF    CAST    IRON. 


especially  those  using1  fine  grades  of  ores,  as  any  stop- 
page of  blast  is  apt  to  cause  a  temporary  chill  and  to 
retard  good  working  of  the  furnace. 

Not  all  grades  or  kinds  of  clay  are  suitable  for  stop- 
ping notches.  It  must  be  of  a  quality  to  withstand 
fire  to  the  best  possible  degree.  Some  use  a  good 
grade  of  fire  clay  and  others  grind  up  old  crucibles  to 
mix  with  the  fire  clay  in  an  effort  to  improve  its  heat- 
resisting  qualities.  The  clay  is  mixed  to  a  consistency 
about  like  that  found  good  for  cupola  stopping  clay, 
and  in  some  places  is  prepared  in  pans  crushed  by 
heavy  rollers. 

The  success  of  stopping  a  notch  by  hand  being  due 
to  the  fact  of  having  the  metal  lower  than  the  level  of 
the  notch,  affords  the  furnace  an 
advantage  not  permitted  to  the 
cupola.  Conditions  in  the  latter 
calling  for  a  '  *  bottom  drop, ' ' 
every  heat  makes  it  most  desir- 
able that  no  metal  should  remain 
in  the  bottom  of  a  cupola  when  a 
heat  is  finished.  For  this  reason 

the  bed  of  a  cupola  as  seen  at  Y,  Fig.  23,  is  generally 
made  on  a  slant,  and  the  tap-hole  placed  at  its  lowest 
level,  as  seen  at  R.  With  such  an  arrangement,  when 
difficulty  in  tapping  and  stopping  once  commences,  it 
often  causes  the  cupola  tender  much  harassing  labor, 
and  the  founder  loss  in  casting.  Any  one  desiring 
further  information  on  tapping  out  and  stopping  up 
cupolas  is  referred  to  ' '  American  Foundry  Practice, ' ' 
page  331. 


CHAPTER  XIII. 

MOULDING  SAND,  CASTING  SAND,  SAND- 
LESS  PIG  IRON  AND    "OPEN 
SAND"  WORK. 

The  many  devices  which  are  employed  by  furnace- 
men  in  controlling  the  distribution  of  20  to  100  tons 
of  molten  metal,  when  tapped,  display  experience  and 
knowledge  which  the  foundry  manager  and  moulder 
can  often  well  utilize  in  founding.  Every  branch  of 
handling  molten  metal  has  its  own  little  '  *  tricks  ' '  in 
practice,  which  have  often  taken  years  to  perfect,  and 
I  propose  now  to  illustrate  some  of  those  involved  in 
controlling  metal  and  making  ' '  open  sand  ' '  moulds 
and  casts  at  a  blast  furnace,  as  the  information  and 
ideas  such  study  imparts,  even  though  furnaces  should 
abandon  casting  pigs  in  sand  beds,  as  referred  to  on 
pages  113  to  1 1 6,  will  prove  of  value  in  many  ways  to 
general  founding. 

A  moulder,  however  well  experienced,  who  has 
never  seen  a  blast  furnace,  would  be  very  liable  to 
make  bad  work  of  things  at  the  start,  should  he  at- 
tempt, without  any  instruction,  to  direct  the  making 
and  casting  off  of  a  floor  of  pigs.  In  preparing  a 
moulding  bed  for  making  pigs,  the  floor  is  dug  out 


100  METALLURGY    OF    CAST    IRON. 

from  2  to  3  feet  deep,  and  then  filled  up  with  a  medi- 
um grade  of  bank  sand,  of  a  very  open,  sandy  nature. 
The  reasons  for  going  down  to  such  a  depth  to  simply 
mold  pigs  that  are  not  more  than  four  inches  deep, 
also  for  using  such  a  coarse  grade  of  sand  having 
very  little  binding  qualities  about  it,  are  found  in  the 
desirability  of  having  conditions  as  favorable  as  pos- 
sible for  permitting  the  escape  of  steam  from  any  ex- 
cess of  moisture  or  water,  which  the  sand  may  contain, 
or  for  draining  downward,  and  hence  lessening  the 
chances  of  a  "boil."  The  moulder  must  bear  in  mind 
that  when  once  a  stream  of  iron  is  started,  the  furnace- 
man  cannot  plug  up  a  "  run-out ' '  or  dampen  the 
ardor  of  a  little  ' '  kick, ' '  the  same  as  when  poiiring  a 
mould,  and  hence  the  precaution  of  not  being  depen- 
dent upon  one's  judgment  to  get  sand  just  the  right 
' '  temper, ' '  etc.  Where  sand  is  as  open  as  is  generally 
used  for  pig  beds,  and  as  deep  in  the  floor  as  above 
described,  water,  after  having  been  absorbed  to  a  cer- 
tain point,  will,  to  a  large  degree,  filter  through  coarse 
sand  towards  the  bottom  of  its  depth,  so  that  should  an 
excess  of  water  have  been  used,  the  chances  are  it  will 
not  cause  the  "  boil  "  it  would  certainly  do  if  the  sand 
was  of  such  a  character  as  that  generally  used  for  green 
sand  molding  in  a  foundry.  Another  point  which 
makes  it  desirable  to  use  such  open-grained  sand  is 
that  of  saving  labor  in  mixing  sands.  About  all  the 
mixing  that  furnace  sand  generally  gets  is  what  the 
force  of  water  from  a  two-inch  nozzle  gives  it.  I  have 
seen  such  a  stream  play  steadily  on  one  spot  for  two 
or  three  minutes  and  no  attention  paid  to  it.  If 
moulding  sand  in  a  foundry  received  such  abuse,  the 
iron  would  mostly  go  to  the  roof  the  moment  it  struck 


MOULDING    AND    CASTING    PIG    IRON,    ETC. 


101 


FIG.    24. 

the  sand.  But  like  all  else  in  mechanics,  there  is  a 
limit  to  abuse,  and  too  much  carelessness  in  wetting 
down  the  floor  of  a  casting  house  can  result  in  disas- 
trous "boils." 

rioulding  pig  beds  is  generally  done  by  three  men, 
who  will  mould  up 
fifteen  to  twenty 
beds  in  about  one 
hour.  The  main 
runner  leading  to 
the  pigs  Nos.  i,  2, 
3,  4,  5,  6  and  7, 
Fig.  29,  page  103, 
is  called  the  ' '  sow 
runner. ' '  There 
are  generally  from 
24  to  28  pigs  to  a 
sow.  Each  sow  is 
leveled,  likewise 
the  pigs  connect- 
ed to  it,  but  each 
bed  is,  in  com- 
mencing from  the 
lower  end,  made  FIG.  27. 


FIG.  25. 


FIG.  26. 


102  METALLURGY    OF    CAST    IRON. 

one  or  two  inches  higher  as  they  approach  the  last 
bed,  so  as  to  conform  closely  to  the  incline  of  the 
main  or  "iron  runner,"  as  it  is  generally  called,  which 
has  a  fall  of  about  eighteen  inches  in  one  hundred 
feet.  A  greater  fall  than  this  would  generally  cause 
the  iron  to  flow  with  too  great  a  rush,  and  should  it 
get  away  from  the  furnace  any  faster  than  usual,  the 
chances  are  it  could  not  be  controlled,  and  instead  of 
its  being  distributed  as  desired  throughout  all  the  pig 
beds,  the  lower  two  or  three  beds  would  be  overflowed, 
and  a  ' '  boil ' '  easily  started  by  reason  of  a  large  area 
of  floor  space  being  all  covered  with  a  plate  of  fluid 
metal,  permitting  no  escape  of  gas  and  steam  from 
the  sand  cores  between  the  pigs.  The  founder  often 
receives  pigs  united  together,  and  often  much  thicker 
in  depth  than  usual.  These  are  called  "  jump  cores," 
and  are  formed  by  reason  of  the  body  of  sand  in 
the  mold  separating  the  pigs,  being  raised  or  pressed 
to  one  side  by  the  action  of  too  quick  a  flow,  poor 
sand,  or  a  little  "boil."  It  has  been  no  uncommon 
occurrence  for  metal  to  come  so  fast  down  the  iron 
runner  that  it  could  not  be  controlled,  and  by  reason 
of  covering  over  a  large  area,  cause  a  whole  tap  to  go 
under  the  drop,  or,  worse  still,  require  dynamite  to 
break  it  up  sufficiently  small  to  be  charged  into  the 
furnace,  along  with  the  ore,  or  sold  for  scrap  metal  to 
be  re-melted  in  air  furnaces  or  big  cupolas. 

The  making  of  the  iron  runner  is  generally  the  work 
of  the  "  keeper."  Figs.  24,  25,  26  and  27  show  differ- 
ent views  of  such  runners,  and  Fig.  34,  page  104,  a 
perspective  view  of  the  whole. 

After  a  furnace  has  been  tapped,  the  metal  often 
comes  slowly,  to  prevent  it  from  chilling  until  its 


MOULDING    AND    CASTING    PIG    IRON,     ETC.  103 


1         2         345617 


•LT   *    *  > 


*'IG.  33-  8  MX^J 


104 


METALLURGY    OF    CAST    IRON. 


speed  is  sufficient  to  fill  the  runner  as  desirable,  a  little 
knoll,  as  at  A,  Fig.  24,  is  generally  formed  in  the 
' '  iron  runner, ' '  as  shown.  This  causes  a  sufficient  body 
of  metal  to  collect  and  keep  itself  fluid  until  the 
flow  is  increased  enough  to  overflow  the  knoll,  by 
which  time  the  chances  are  the  flow  will  have  in- 
creased to  such  a  degree  as  to  send  a  fair  stream 


FIG.   34. — PERSPECTIVE   VIEW    OF    A  CASTING    HOUSE. 

down  the  iron  runner.  The  iron  in  first  flowing  down 
the  runner  carries  more  or  less  slush  of  iron  and  dirt 
in  the  front  of  its  stream.  This  will  often  pile  up  so 
as  to  require  to  be  broken  by  means  of  a  wooden  pole 
in  the  hands  of  a  man,  as  seen  in  Fig.  34.  As  soon  as 
the  metal  has  reached  and  filled  the  lower  bed,  a  "  cut- 


MOULDING    AND    CASTING    PIG    IRON,   ETC.  105 

ter, "  as  shown  at  Fig.  30,  and  in  the  hands  of  the 
man  at  the  left  in  Fig.  34,  is  then  quickly  placed 
with  pressure  so  as  to  be  bedded  into  the  main  run- 
ner, as  seen  at  B,  Fig.  24.  A  few  moments  before  this 
is  done  a  man  with  a  ravel,  as  seen  at  Fig.  34,  pulls 
away  the  mound  of  sand,  closing  the  connection  from 
the  "  iron  runner  "  to  the  "  sow,"  as  seen  at  C  and  D, 
Fig.  24,  also  at  E,  Fig.  29,  to  make  an  opening,  as 
seen  at  F,  Fig.  24.  The  top  level  of  the  pig  beds 
should  be  below  the  level  of  the  bottom  of  the  main 
runner  in  order  that  all  the  metal  may  be  drained  from 
the  main  runner;  and,  again,  the  pig  beds  should 
not  be  too  far  below  the  level  of  the  bottom  of  the 
main  runner,  as  this  would  cause  the  metal  to  rush 
from  the  main  runner  to  the  sow  with  a  force  very 
liable  to  cut  up  the  sand  where  the  metal  would  strike 
the  bottom  level,  or  wash  away  the  cores  between  the 
pigs.  The  distance  sought  for  is  about  that  shown  in 
the  cuts,  Figs.  28  and  29.  If  the  moulder  would  con- 
sider trying  to  make  a  mould  with  what  is  generally 
termed  a  medium  grade  of  bank  sand,  having  the  life 
pretty  well  burned  out  of  it,  he  would  then  be  in  a  posi- 
tion to  understand  how  easily  a  rush  of  metal  could  cut 
up  a  pig  bed  of  moulds,  and  the  necessity  for  having 
certain  conditions  prevail,  even  if  it  is  only  ' '  pigs  ' ' 
that  are  being  moulded  and  cast.  As  the  metal 
flows  down  the  runner,  much  of  the  sand  floats  with 
the  iron ;  but  as  pigs  are  not  finished,  or  condemned,  if 
they  are  a  little  rough  on  their  surface  from  dross 
or  sand,  there  are  no  serious  objections  as  long  as 
it  is  not  sufficient  to  impede  its  passage  to  the  pigs. 
At  H,  Fig.  29,  is  seen  the  "  ravel  "  as  it  is  placed 
in  the  sand  ready  to  make  an  opening  to  admit 


106  METALLURGY    OF    CAST    IRON. 

the  molten  metal  from  the  main  runner  to  the  sow. 

At  Fig.  3 1  are  shown  what  are  called  * '  runner  sta- 
ples, ' '  which  are  used  to  support  the  '  *  cutters, ' '  as  seen 
at  Nos.  i,  2,  3,  4,  5,  and  6,  Figs.  24  and  28,  also  in  the 
perspective  view  of  the  main  runner  seen  in  Fig.  34. 
As  each  pig  bed  fills  up,  the  cutters  stop  the  flow  of 
metal,  permitting  it  to  flow  into  the  adjoining  bed  as 
above  described.  When  half  of  the  beds  are  about 
poured  off,  slag  then  commences  to  come  out  with  the 
iron  at  the  notch-hole.  To  prevent  the  slag  from  pass- 
ing down  the  runner  to  the  pig  beds,  a  "  skimmer 
plate,"  seen  at  I,  Fig.  24,  is  knocked  down  to  about  the 
depth  shown  and  then  some  sand  is  thrown  against  it 
on  the  side  at  K.  By  ramming  this  sand,  the  opening 
below  the  lower  edge  of  the  skimmer  plate  I  and  the 
bottom  of  the  runner  can  be  decreased  at  will,  so  that 
only  iron  may  pass  beyond  the  skimmer  plate  and  its 
flow  may  be  regulated.  The  slag  is  let  run  out  at  the 
"  slag  runner  "  shown  at  the  dotted  lines  K,  Fig.  24.. 
The  slag  running  out  of  the  tap-hole  at  every  cast  is 
considerable;  often  for  every  ten  tons  of  iron  there 
may  be  two  tons  of  slag. 

After  the  pigs  are  cast  they  must  be  broken.  This 
constitutes  the  most  laborious  work  about  a  furnace. 
Before  starting  to  break  the  pigs,  which  is  not  done 
until  they  have  solidified  sufficiently  to  not  "  bleed," 
sand  to  a  depth  of  about  %  inch  is  thrown  over  their 
surface.  Two  or  three  men  wearing  wooden  soles 
about  \y2  inches  thick  attached  to  their  shoes,  now 
start  at  the  first  poured  bed  with  pointed  i^-inch 
bars  about  six  feet  long.  By  inserting  the  point  of 
the  bar  between  the  pigs  at  the  end  furthest  from 
the  *  *  sow, ' '  they  are  readily  broken  loose  from  the 


MOULDING    AND    CASTING    PIG    IRON,     ETC.  107 

sow.  After  the  pigs  are  all  separated,  the  sow  is  then 
broken  by  taking  the  ends  of  the  pigs  of  the  next 
row  as  a  rest  to  pry  the  sow  up;  if  not  broken  by 
being  lifted,  a  sledge  is  then  used.  When  two  to 
three  men  will  separate  about  five  hundred  pigs  and 
break  about  eighteen  sows  in  several  pieces  in  about  a 
half -hour's  time  and  not  seem  in  any  hurry,  it  is  safe 
to  conclude  that  the  work  is  done  by  a  very  commend- 
able system. 

After  the  pigs  and  sows  are  broken  as  above  de- 
scribed, a  stream  of  water  is  turned  on  to  cool  them  off 
so  that  they  can  be  handled  and  removed  from  the  cast- 
ing house  in  time  to  permit  the  bed  being  re-moulded 
for  its  next  turn  in  casting.  This,  in  a  furnace  of  the 
size  as  seen  on  page  49,  making  five  taps  every  24 
hours,  leaves  but  about  three  hours  for  the  * '  iron  car- 
riers ' '  to  break  up  and  load  on  buggies,  for  removal 
from  casting  house,  about  40  tons  of  pig  metal.  To 
permit  a  buggy  being  brought  close  to  the  iron  to  be 
loaded,  a  wooden  track  fastened  together  in  sections  of 
about  10  feet  is  laid  down  on  the  casting  floor  to  any 
length  or  turn  desired.  There  are  always  two  floors  to 
a  casting  house,  so  as  to  permit  one  being  molded  and 
got  ready  for  a  cast  while  the  other  is  being  relieved  of 
its  pig  metal  and  wet  down  ready  for  molding.  A  cast- 
ing house,  as  it  generally  appears  about  one-half  hour 
before  casting  time,  is  seen  in  Fig.  34.  The  keeper 
seen  standing  by  the  notch  of  the  furnace  has 
his  runner  made  with  the  runner  staples  and  cutters 
in  position.  The  man  on  the  right,  at  the  lower  end 
of  the  runner,  is  shown  just  finishing  the  ramming 
of  the  last  bed  of  pigs.  To  afford  an  idea  of  cast- 
ing, the  first  man  on  the  left  of  the  main  runner  is 


108  METALLURGY    OF    CAST    IRON. 

shown  standing  ready  to  drive  the  cutter  into  the 
runner  to  stop  the  metal  from  flowing  to  the  first  bed. 
The  second  man  seen  on  the  left  stands  ready  to  ravel 
out  the  branch  runner  to  the  pig  bed.  The  third  man 
having  a  pole  in  his  hand  is  supposed  to  be  breaking 
up  the  crust  of  slush  formed  in  the  front  of  the  metal 
as  it  first  comes  down  the  main  runner.  These  last 
three  men  are  simply  placed  in  position  shown  to  illus- 
trate their  work,  as  if  metal  had  been  actually  running 
down  the  runner  as  above  described.  To  those  never 
having  seen  a  casting  house,  Fig.  34  should  give  a 
general  idea  of  the  methods  employed  for  moulding 
and  casting  pig  metal. 

Moulders  are  often  employed  at  a  furnace  to  make 
moulds,  open  and  closed,  to  be  poured  with  metal  as  it 
comes  down  the  runner.  How  to  regulate  the  flow 
so  as  to  stop  it  as  soon  as  the  mould  is  filled  is  a  trick 
often  worth  knowing  for  application  even  in  a  foun- 
dry. At  Fig.  26  is  seen  a  section,  through  A  B  of  Fig. 
27.  The  moulds  shown  are  supposed  to  be  "  open 
sand  ' '  plates,  which  should  be  as  uniform  in  thick- 
ness as  possible.  By  the  plan  shown,  if  the  metal  is 
as  *  *  hot  "as  is  generally  obtained,  the  plates  can  be 
made  not  to  vary  over  y%  inch  in  thickness,  which  is 
as  close  as  a  founder  can  generally  run  them  where  he 
has  metal  in  a  ladle  supposed  to  be  under  perfect  con- 
trol. To  explain  this  principle,  attention  is  first 
called  to  Fig.  25,  which  is  a  section  of  the  main  run- 
ner. At  the  dotted  lines  N  and  M  is  seen  the  depth 
to  which  the  branch  runners  connecting  the  sow  and 
main  runner  are  generally  made  and  which  are  sup- 
posed to  drain  all  the  metal  from  the  main  runner  until 
"  cut  off  "  by  the  "  cutters  "  B,  as  seen  in  Figs.  24  and 


MOULDING    AND    CASTING    PIG    IRON,    ETC.  109 

28.  By  making  a  comparison  in  the  depth  of  the  open- 
ing P  with  M  and  N,  Fig.  25,  it  will  be  seen  that  the 
opening  at  P  could  not  deliver  any  metal  unless  the  iron 
was  raised  in  the  runner  to  its  level,  and  the  chances 
are,  in  the  general  working,  that  the  iron  in  the  main 
runner  might  never  reach  the  bottom  of  the  opening 
at  P.  But  to  compel  it  to  do  so,  a  stopper  composed 
of  slag,  chilled  on  the  end  of  a  one-inch  iron  rod,  as 
seen  at  S,  Figs.  25  and  27,  is  placed  in  the  main  run- 
ner to  impede  the  flow  of  the  metal.  This  action  raises 
the  height  of  the  metal  in  the  runner  so  as  to  make  it 
flow  out  at  P,  and  the  moment  the  stopper  S  is  lifted, 
the  metal  is  lowered  below  the  level  of  this  outlet, 
and  hence  instantly  ceases  to  flow  into  any  mould 
which  may  be  run  by  such  a  plan.  This  last  method 
governs  well  the  actions  of  the  main  runner  in  filling 
moulds;  but  there  is  still  another  point  to  guard 
against  where  two  or  more  castings  are  poured  from 
such  a  branch  runner,  and  this  is  the  tendency  of  one 
mould  to  fill  before  another,  and  hence  produce  castings 
thicker  or  thinner  than  might  be  desired.  To  regu- 
late this  point,  a  portion  of  the  edge  of  the  mould  is 
cut  away  to  the  thickness  desired,  as  seen  at  B  in  the 
plan  view,  Fig.  27,  and  also  in  the  section  A  B,  Fig. 
26.  Such  moulds  being  generally  raised  above  the 
level  of  the  floor,  it  can  be  readily  conceived  that  any 
overflow  at  the  points  B  will  be  received  at  a  lower 
level  than  that  of  the  castings,  hence  the  difficulty,  with 
good  metal,  of  obtaining  such  castings  thicker  than  they 
might  be  desired.  It  may  be  well  to  state  that  out- 
lets, such  as  at  P,  should  be  made  well  up  towards  the 
upper  end  of  the  main  runner,  so  that  when  the  stop- 
per S  is  lifted  the  metal  will  have  a  good  chance  to 


110  METALLURGY    OF    CAST    IRON. 

run  down  the  runner  and  fill  the  pig  beds  through 
lower  outlets,  as  at  N  and  M.  The  dotted  lines  O  O, 
in  Figs.  24  and  25,  are  supposed  to  be  level,  and  the 
angle  of  the  main  runner  shows  the  incline  from  this 
level  line. 

A  plan  of  the  pattern  is  seen  at  T,  Fig.  33.  The  recess 
at  A  is  to  assist  the  pigs  being  broken  in  two  pieces 
when  cold,  and  the  formation  as  seen  at  B  where  the 
pig  and  sow  join  to  make  their  separation  at  this  point 
easy  when  breaking  the  iron  after  a  cast.  The  same 
number  of  patterns  are  used  as  there  are  pigs  to  be 
moulded  in  a  bed.  A  good  method  of  forming  these 
patterns  is  by  a  combination  of  sheet  steel,  and  wood. 
The  steel  which  forms  the  outside,  as  shown  by  the 
heavy  black  line  at  P,  is  about  -£%  inch  thick,  and  formed 
to  shape  over  an  iron  block  before  the  wood  is  secured, 
as  shown  at  V  V  and  at  S,  the  latter  being  a  i  ^  -inch 
piece  of  hard  wood,  secured  by  wood  screws  passing 
through  the  steel  at  the  upper  edge  of  every  4  inches 
into  the  wood  board.  To  secure  the  pattern  at  its  end, 
a  ^-inch  rod  passes  clear  through  each  end  and  is  riv- 
eted. This  method  makes  a  very  light  pattern,  and 
one  which  will  last  for  years,  and  discounts  a  dozen 
times  over  the  old  plan  of  making  all-wooden  patterns, 
which  are  still  used  by  some.  The  principle  involved 
in  the  construction  of  these  patterns  is  one  the  founder 
and  patternmaker  might  often  well  utilize.  The  sow 
pattern  is  made  of  a  continuous  stick  of  timber,  having 
one  side  at  T  faced  with  a  sheet  of  ^6 -inch  steel,  so  as 
to  prevent  warping  of  the  pattern.  There  is  also  a  piece 
of  iron  ^  x  2  inches  set  in  and  screwed  down  on  the 
top  surface  of  the  sow  pattern,  as  seen  at  K,  for  the 
purpose  of  leveling ;  as  constant  friction  of  a  level  on 


MOULDING    AND    CASTING    PIG    IRON,    ETC.  Ill 

the  surface  of  wood  would  cause  it  to  splinter  and  be 
uneven  for  leveling  purposes. 

In  using  these  patterns  and  bedding  them  in  the 
floor,  there  is  no  heavy  sledge  hammer  used  to  settle 
them,  as  a  moulder  generally  does  with  his  patterns. 
In  fact,  no  sledge  or  hammer  is  used  on  them,  the  only 
thing  leveled  is  the  sow ;  if  one  end  is  high,  the  pat- 
tern may  be  lifted  and  sand  scraped  away  from  under 
it,  or  the  low  end  may  be  raised  and  sand  tucked  under 
it  by  means  of  the  handle  end  of  the  shovel  or  a  push  of 
the  foot.  The  sow  having  been  leveled,  the  pig  patterns 
are  then  laid  down  on  the  floor,  which  has  previously 
been  leveled  off  with  a  shovel  as  near  as  the  eye  can 
judge,  and  which  is  generally  done  truer  than  many 
of  our  moulders  are  capable  of  doing.  When  the  pat- 
terns are  all  in  place,  sand  "  riddled  through  the 
shovel"  fills  up  the  space  between  them,  and  a  man 
with  a  rammer  1 2  inches  long,  as  seen  at  the  right,  in 
Figs.  32  and  34,  rams  the  sand  between  the  patterns. 
After  going  over  with  this  rammer  once,  sand  is  then 
shoveled  over  the  bed,  and  a  flat  scraper  18  inches  long 
scrapes  the  sand  off  level  with  the  top  surface  of  the 
patterns,  which  is  all  the  packing  or  sleeking  the  sur- 
face or  joint  of  the  bed  receives.  Sand  having  been 
pushed  with  the  back  of  the  scraper  to  raise  a  mound 
of  sand  between  the  pig  beds  to  prevent  metal  flowing 
over,  the  sow  pattern  is  now  drawn  out  by  means  of 
the  lifting  iron  seen  at  D,  Fig.  33.  The  sow  having 
been  removed,  the  pig  patterns  are  then  drawn  out  by 
first  raising  one  end  with  the  hand  in  the  recess  at  the 
end  R  until  they  can  be  lifted  by  the  center,  when 
they  are  tossed  on  to  the  next  bed  ready  to  be  set  up 
for  another  filling  of  sand.  Some  moulders  might  feel 


112  METALLURGY    OF    CAST    IRON. 

like  asking,  "Was  there  no  swab  used?"  No,  the 
wetting  the  joint  receives  is  as  if  by  chance  the  fellow 
on  the  other  side  of  the  house  wetting  down  the  floor 
should,  in  turning  around  carelessly,  throw  a  stream 
of  water  over  the  joint.  I  do  not  wish  to  be  under- 
stood as  saying  that  because  pigs  can  be  made  with 
such  apparent  carelessness,  rapidity  and  little  labor, 
the  moulder  should  do  the  same  in  making  "  open' 
sand"  work  in  a  foundry;  but  nevertheless  the  prin- 
ciples involved  should  be  studied  by  those  moulders 
who  require  a  whole  hour  to  make  about  a  dozen  cast 
"gaggers." 

flodern  moulding  and  casting  of  pig  metal  involve 
points  which  the  founder  can  often  utilize  to  advan- 
tage. The  principle  involved  in  using'Open  grades  of 
sand  and  having  deep  floors  to  afford  a  chance  for  ex- 
cessive moisture  or  water  to  pass  downward,  is  one 
the  founder  having  much  * '  open  sand  ' '  work  to  do 
can  often  well  adopt.  How  frequently  do  we  find 
moulders  making  ' '  open  sand  ' '  castings  that  ' '  kick  ' ' 
and  ' '  bubble  ' '  in  such  a  manner  that,  when  the  cast- 
ings come  out,  it  is  a  question  whether  they  came 
from  a  foundry  or  furnace  "boil."  Drop  close  grades 
of  moulding  sand  and  adopt  a  sharp  open  sand,  and 
use  regular  moulding  sand  only  where  the  metal 
from  the  pouring  basin  strikes  the  flat  surface  of  the 
mould,  and  the  trouble  as  above  described  with  "open 
sand"  work  in  a  foundry  will  decrease. 


CHAPTER  XIV. 

CHILLED   OR   SANDLESS   PIG   IRON    AND 
ITS  ADVANTAGES. 

Casting  pig  iron  in  sand  moulds  is  objectionable  in 

many  ways.  To  overcome  these  objections  there  have, 
since  1896,  been  several  different  methods  adopted  for 
casting  the  metal  in  chills  instead  of  sand  moulds,. aside 
from  the  practice  of  casting  in  chills  placed  in  the  floor 
of  a  casting  house,  which  some  follow,  especially  as 
used  for  making  basic  pig  iron.  The  principle  involved 
in  the  latest  improvement  lies  in  having  iron  moulds, 
the  form  of  pigs  arranged  on  a  movable  table,  etc.,  so 
that  the  metal  first  running  from  the  furnace  into 
ladles  can  be  poured  into  the  pig  moulds ;  after  which, 
by  self-dumping  devices,  they  may  carry  the  pig 
iron  into  cars  ready  for  shipment.  This  saves  the 
arduous  labor  of  breaking  the  hot  pigs  and  sows  in  the 
casting  house  and  then  handling  them  by  hand  tc 
remove  the  pigs  from  the  casting  floors,  and,  aside 
from  this,  produces  pigs  which  do  not  require  break- 
ing, and  is  also  free  of  sand  and  scale,  the  advantages 
of  which  are  stated  on  the  next  page. 

There  are  several  machines  on  the  market,  among 
which  are  those  patented  by  Mr.  E.  A.  Uehling,  Mr.  R. 
W.  Davies,  and  Mr.    H.  R.  Geer.     A  large  number  of 
furnaces  are  now  using  these  different  machines,  ai  d 
it  is  probable  that  many  more  will  do  so  in  the  futui- 


114  METALLURGY    OF    CAST    IRON. 

The  first  edition  of  this  work  recommended  the  adop- 
tion of  these  casting  machines,  and  all  that  was  said  in 
their  favor  has  been  verified  by  practice. 

The  economy  and  advantage  to  be  obtained  by  using 
chilled  or  sandless  pig  metal  in  foundries,  steel  works, 
etc.,  maybe  stated  as  follows:  First,  being  a  harder 
iron  by  reason  of  its  chill  or  density,  which  holds  the 
carbon  more  in  a  combined  form,  as  well  as  having 
pigs  free  of  sand  (silica),  less  time  and  fuel  will  be 
required  to  melt  it.  Second,  the  pig  being  sandless 
there  will  be  less  fluxing  needed  and  less  slag  to  take 
care  of  in  large  heats ;  this  will  also  give  a  cleaner  iron 
to  pour  moulds,  whether  for  small  or  large  heats. 
Third,  being  a  chilled  iron  or  more  dense  it  will  give 
a  softer  re-melt  than  if  the  furnace  iron  had  been  cast 
in  sand  moulds.  This  is  a  discovery  made  by  the 
author,  the  details  of  which  are  found  on  page  338. 
Fourth,  by  pouring  furnace  metal  from  ladles,  better 
mixed  metal  will  be  obtained  in  a  car  or  cast  of  pig  iron 
than  by  casting  pigs  in  sand  moulds.  The  value  of  this 
will  be  better  understood  by  reading  Chapter  XVIII. 

Some  founders,  understanding  by  experience  the 
value  of  having  the  iron  charged  into  cupolas  as  free 
of  sand,  scale,  or  dirt  as  possible,  go  to  the  labor  of 
tumbling  all  their  gates,  etc.  Could  such  founders 
also  secure  their  pig  iron  free  of  sand,  they  could  derive 
still  greater  benefit  by  having  clean  iron  to  re-melt  and 
pour  into  their  castings.  What  sandless  pig  the  author 
has  used  proved  much  preferable  to  sand  pigs  in  several 
ways.  This  experience  is  endorsed  by  others,  as  can  be 
seen  by  the  following  extracts  from  a  few  letters  which  he 
obtained  during  1899  by  courtesy  of  Mr.  Edgar  S.  Cook, 
president  of  the  Warwick  Iron  Co.  of  Pottstown,  Pa. 


ADVANTAGES  OF  CHILLED  OR  SANDLESS  PIG  IRON.      115 

A  stove  manufacturer  says:  "  From  the  experience 
we  have  had  we  believe,  thus  far,  that  you  can  be  sure 
there  is  one  foundrvman  who  does  not  fear  the  sandless 

Pig." 

A  prominent  tool  builder  says :  ' '  We  have  tried  the 
sandless  iron  and  find  it  very  nice.  You  may  ship 
more  on  our  orders. ' ' 

The  head  of  a  large  ship-building  concern  says:  "  I 
am  pleased  to  say  that  your  sandless  pig  is  very  satis- 
factory. I  hope  hereafter  you  will  always  ship  me  sand- 
less  pig,  it  saves  a  good  bit  of  trouble  in  the  cupola. ' ' 

A  stove  works  says :  * '  We  have  watched  the  results 
very  carefully  thus  far,  and  find  it  most  satisfactory. 
The  only  objection  we  have  to  the  *  sandless  iron  '  is 
that  the  pigs  are  too  heavy  and  hard  to  break.  Our 
cupola  men  can  hardly  handle  them,  as  our  facilities  are 
such  that  the  short,  heavy  pigs  of  the  sandless  iron  cannot 
be  broken,  otherwise  we  are  very  much  pleased  with  it. ' ' 

With  reference  to  the  complaint  that  sandless  pigs 
are  too  large,  this  has  been  remedied  in  some  of  the 
machines  so  as  to  make  the  pigs  of  a  convenient  size 
for  all  cupolas  over  thirty  inches  inside  diameter.  It 
is  not  to  be  understood  that  all  chilled  or  sandless  pig 
will  show  white  fractures  should  they  be  broken ;  this 
will  largely  depend  upon  the  percentage  of  silicon  and 
sulphur  in  the  iron.  Iron  above  1.20  silicon  and  not 
over  .04  in  sulphur,  with  manganese  below  1.25,  will 
rarely  show  any  chill,  but,  of  course,  be  more  dense  or 
higher  in  combined  carbon  than  if  the  same  iron  was 
cast  in  sand  moulds.  Cuts  of  sand  and  chilled  cast 
pig  are  shown  in  Figs.  35  and  36.  These  cuts  were 
originally  presented  by  Mr.  Alfred  Ladd  Colby  in  the 
Iron  Trade  Review,  June  13,  1901. 


i6 


METALLURGY    OF    CAST    IRON. 


As  far  as  saving  of  labor  and  other  expenses  is  con- 
cerned, the  casting  machines  do  not  prove  as  advan- 
tageous as  some  other 
improvements  in  mak- 
ing pig  iron ;  however, 
they  dispense  with  the 
hardest  labor  and  give 
a  product  that,  in 
many  cases,  is  much 
more  desirable  than 
sand  pig.  For  this 
reason  their  use  will 
continue  to  increase, 
but  probably  will  not 
do  away  with  sand 
pigs  entirely;  at  least, 
most  of  the  furnaces  not  using  floor  chills  will  be  required 
to  keep  sand  beds  in  order  to  take  care  of  their  metal 


FIG.  35. —  SAND   CAST   PIG. 


FIG.   36. —  MACHINE   CAST   PIG   IRON. 

in  case  of  accidents  to  the  machine.  For  this  and 
other  reasons  the  author  has  thought  it  well  to  retain,  in 
this  revision,  the  information  in  the  preceding  chapter. 


CHAPTER  XV. 

UTILITY    OF    DIRECT    METAL    FOR 
FOUNDING. 

In  the  first  days  of  founding,  castings  were  made 
from  metal  taken  directly  from  the  furnace  making 
the  iron.  The  difficulty  and  uncertainty  of  obtaining 
the  grade  of  iron  desired  and  the  fluidity  necessary  to 
insure  good  work,  as  well  as  the  advantage  of  having 
metal  at  the  time  best  suited  to  the  founder's  needs, 
gave  rise  to  the  origination  of  the  cupola  to  re-melt 
iron.  Had  the  furnace  advanced  anywhere  near  the 
degree  in,  assuring  a  uniformity  of  "  grade  "  that  it 
has  in  increasing  its  output  many  more  castings  would 
now  be  made  direct  from  furnace  iron.  While  some 
may  question  the  ability  of  the  furnace  to  ever  achieve 
any  better  results  in  always  obtaining  a  uniformity  of 
product,  competition  may  strongly  influence  an  effort 
for  improvement  in  this  direction.  Aside  from  the 
above  evil  is  that  of  the  trouble  caused  by  the  ' '  kish  ' ' 
found  with  some  metals  that  throw  out  graphite  exces- 
sively. Often  after  a  furnace  * '  cast ' '  of  Foundry  or 
Bessemer  the  floor  of  the  house  will  be  covered  with 
' '  kish, ' '  which  resembles  in  appearance  flakes  of  silver 
lead  or  plumbago,  and  are  like  the  flakes  of  carbon 
so  often  found  between  grains  of  pig  metal  and  cast- 
ings. It  can  be  removed  from  fractures  by  means  of 
a  stiff  brush  or  rubbing. 


Il8  METALLURGY    OF    CAST    IRON. 

The  evils  to  be  expected  from  metal  possessing  much 
"  kish  "  are  mainly  in  "cold  shuts,"  spongy,  porous 
spots  in  castings,  or  the  separation  of  the  grains  of 
the  metal  at  places  where  "kish"  is  confined.  One 
might  as  well  try  to  make  a  union  of  oil  and  water  as 
of  kish  and  cast  iron.  Were  it  possible  to  collect  or 
skim  off  all  the  '  *  kish  ' '  created  on  top  of  direct  metal, 
little  damage  might  be  expected ;  but  this  is  not  prac- 
tical, as  the  ' '  kish  ' '  keeps  rising  to  the  surface  as  long 
as  the  metal  is  in  a  fairly  fluid  condition.  Appliances 
have  been  invented  with  a  view  to  collect  the  * '  kish  ' ' 
in  pouring  runners,  etc. ,  before  the  metal  would  enter 
the  moulds,  but  these  have  proven  of  little  value.  It 
may  be  said  that  metal  possessing  much  * '  kish  ' '  is 
unfit  for  pouring  castings. 

Direct  metal  free  of  "kish"  can  make  very  good 
castings,  and  for  some  classes  of  work  might  often 
prove  more  desirable  than  cupola  iron,  as  less  sulphur 
can  be  obtained  in  direct  metal  than  with  iron  re- 
melted.  Iron  cannot  be  re-melted  in  the  cupola, 
with  coke  or  coal,  without  increasing  its  sulphur 
from  .02  to  .06  points.  The  re-melting  of  pig  metal 
entirely  destroys  the  *  *  kish  ' '  that  appears  in  direct 
metal. 

The  life  and  fluidity  of  direct  metal,  compared 
to  cupola  iron,  are  qualities  some  will  question.  If 
a  furnace  is  working  properly,  its  product  will  compare 
very  favorably,  as  regards  these  qualities,  with  cupola 
iron.  The  author  has  seen  hotter  iron  from  a  furnace 
than  is  generally  obtained  from  cupolas  that  hold  its 
life  or  fluidity  exceptionally  long.  In  fact,  the  author 
is  of  the  opinion  that  direct  metal  can  have  such  an 
initial  heat  imparted  to  it  as  to  create  a  much  greater 


UTILITY    OF    DIRECT    METAL    FOR    FOUNDING.  119 

life  to  the  fluidity  of  the  metal  than  can  be  obtained  in 
re-melted  iron. 

To  utilize  direct  metal,  some  have  thought  it  would 
be  a  good  plan,  in  order  to  overcome  the  difficulty 
from  '  *  kish  ' '  and  obtain  a  more  uniform  product,  to 
first  pour  the  metal  coming  from  two  or  more  furnaces 
into  a  large  receiver  or  reservoir  so  arranged  as  to 
closely  confine  from  50  to  100  tons  of  iron,  one  idea 
being  that  if  the  metal  should  have  ' '  kish  ' '  in  one  fur- 
nace, another  would  be  free  of  it  to  mix  with  it,  and 
hence  an  average  could  be  obtained  which  would  be 
sufficiently  free  from  ' '  kish  ' '  to  obviate  any  defects 
in  the  casting.  The  information  which  the  writer  has 
obtained  as  to  the  success  of  this  plan  is  not  very 
favorable.  The  difficulty  found  consisted  in  the  metal 
losing  too  much  fluidity  and  life  by  the  extra  handling 
and  detention  of  the  metal  in  the  fluid  state.  Where 
work  is  very  massive,  not  requiring  good  ' '  hot  iron, ' ' 
this  reservoir  method  may  be  of  much  value ;  but  the 
difference  which  exists  in  the  cost  of  direct  metal  and 
cupola  iron  does  not  warrant  any  very  great  chances 
being  taken  in  losing  castings  on  account  of  the  fluidity 
and  uniformity  of  a  "  grade  ' '  not  being  as  desired. 
However,  for  castings  like  ingot  moulds  and  pipes, 
''direct  metal"  in  days  of  close  margins  may  com- 
mand attention  in  some  cases. 

It  is  no  uncommon  thing  for  us  in  our  foundry  to 
make  small  castings  with  direct  metal  carried  by  three 
men  in  a  "  bull  ladle,"  taken  from  a  furnace  close  by 
us.  The  plan  which  we  adopt  to  obtain  such  small 
bodies  of  metal  is  simply  to  catch  the  metal  with  a 
*  *  hand  ladle  ' '  by  dipping  the  iron  out  of  the  main 
runner  as  it  flows  to  the  pigs  and  pouring  it  into  a 


120  METALLURGY    OF    CAST    IRON. 

11  bull  ladle. "  We  have  made  very  good  castings  by 
this  plan.  We  have  also  taken  ' '  direct  metal ' '  in  crane 
ladles  by  having  a  car  run  on  a  track  sunk  sufficiently 
below  the  main  runner  to  receive  the  metal  from  a 
branch  runner  extending  beyond  the  casting  house. 
With  iron  containing  silicon  under  i .  oo,  manganese  up 
to  i. oo,  the  higher  the  better,  and  sulphur  above  .03,  it  is 
rare  that  any  kish  is  seen,  and  when  such  direct  metal  can 
be  obtained  very  good  castings  can  be  produced.  Of 
course,  with  a  low  silicon  and  high  sulphur  iron  it  is 
not  to  be  expected  that  any  work  less  than  half  an 
inch  thick,  requiring  any  fine  finishing  in  the  machine 
shop,  can  be  satisfactorily  obtained,  but  for  bodies 
over  the  above  thickness  very  little  trouble  should  be 
experienced,  as  long  as  the  metal  does  not  get  over  one 
per  cent,  in  silicon  and  keeps  up  in  manganese  and  sul- 
phur. As  seen  by  study  of  Chapter  XVII.,  it  is  the 
changeable  percentages  of  silicon  and  sulphur  which,  as 
a  rule,  alter  the  grade  in  the  product  of  a  furnace  when 
running  on  one  kind  of  ore,  flux,  and  fuel.  Late 
improvements  and  a  better  understanding  of  furnace 
work  is  doing  much  to  lessen  irregularity  in  the  per- 
centages of  silicon  and  sulphur.  In  fact,  some 
furnacemen  have  so  mastered  the  art  of  making  iron 
that  they  can  run  weeks  at  a  time  without  varying  30 
per  cent,  in  silicon  or  three  points  in  sulphur,  when 
making  iron  having  less  than  1.25  silicon.  It  is  with 
silicon  above  1.50  per  cent. —  also  in  very  hot  weather, 
as  shown  by  Chapter  XVII.  —  that  the  greatest  diffi- 
culty is  experienced,  at  present,  in  regularly  obtaining 
a  uniform  grade  of  pig  metal. 


CHAPTER  XVI. 

BANKING  FURNACES  AND  CUPOLAS. 

The  principle  involved  in  «» banking"  is  simply  to 
do  everything"  possible  to  prevent  air  rinding  access 
through  the  body  of  a  furnace  to  the  fuel,  so  as  to 
stop  rapid  combustion  and  sustain  the  fire  only  in  a 
dormant  state  until  it  is  found  desirable  to  again 
*  *  blow  in  ' '  the  furnace.  This  is  similar  in  principle 
to  the  practice  of  smothering  a  fire  in  a  stove  over 
night  so  that  next  morning  little  labor  or  fuel  would 
be  required  to  start  a  good  fire  and  provide  a  quick 
breakfast.  The  old  plan  of  "banking"  a  furnace  in- 
volves considerable  labor  and  expense.  One  system 
followed  is  to  encircle  the  furnace  with  a  curbing  of 
plates  bolted  together,  or  planks  stood  on  end,  pro- 
jecting 2  or  3  feet  above  the  tuyeres,  the  planks  be- 
ing held  together  by  means  of  hemp  or  wire  ropes, 
the  space  between  the  furnace  and  the  curbing  being 
about  2  feet,  which  is  filled  up  with  a  close  grade  of 
sand.  Before  encircling  the  furnace  with  this  curb- 
ing, the  slag  pipe  and  the  tuyeres  are  all  taken  out 
and  all  their  pipe  connections  removed.  (The  pipe 
connections  to  the  coolers  are  not  disturbed,  as  water 
is  left  on  them  during  the  time  of  "banking. ")  After 
this  the  tuyere  holes  in  the  brickwork,  etc. ,  are  filled 


122  METALLURGY    OF    CAST    IRON. 

with  clay.  This  system  makes  it  almost  impossible 
for  any  air  to  find  access  to  fuel  in  the  hearth,  where 
so  many  openings  for  tuyeres,  etc. ,  would  leave  crev- 
ices for  air  to  enter.  The  stack  portion  being  practi- 
cally a  solid  body  enclosed  by  a  tight  shell  of  iron,  no 
attention  is  given  to  it ;  so  also  with  the  bell  and  hop- 
per at  the  top  of  the  furnace,  as  some  ventilation  is 
desirable  at  the  top  to  allow  any  excess  of  gas  to  free- 
ly escape.  For  this  purpose,  the  "bleeder"  pipe  valve 
can  be  forced  open,  as  in  no  case  is  the  "down  comer" 
valve  opened.  From  this  "bleeder"  the  state  of  the 
fire  in  the  furnace  can  also  be  fairly  judged.  Nearly 
all  furnacemen  differ  somewhat  in  their  methods  of 
"banking."  At  the  present  day  many  have  aban- 
doned the  practice  of  encircling  a  furnace  with  a 
curbing  above  described,  and  after  removal  of  the 
tuyeres  and  pipes  they  simply  pack  all  holes  and  crev- 
ices with  clay  rammed  tightly  in  place,  and  then  oc- 
casionally wash  the  outside  of  the  lining  or  brick- 
work, which  is  exposed  to  the  air,  with  a  thick  coat 
of  clay  wash,  thus  closing  up  all  crevices  or  pores 
which  might  admit  air  to  the  fuel.  This  plan,  while 
costing  much  less  than  the  curbing  system,  has  been 
found  sufficiently  effective  to  answer  all  purposes.  In 
preparing  the  furnace  for  being  "banked,"  it  is  essen- 
tial to  free  it  as  much  as  possible  from  its  regular 
charges,  and  any  liquid  metal  which  may  be  in  the 
hearth  below  the  tapping  hole. 

To  liberate  the  liquid  metal  all  that  is  possible  from 
the  bed  of  the  furnace,  a  hole  is  sometimes  made 
from  one  to  two  feet  below  the  level  of  the  top  of  the 
regular  tapping  hole,  which  permits  the  metal  to  run 
out  into  an  excavation  in  the  ground  in  the  form 


"  BANKING"  FURNACES  AND  CUPOLAS.  123 

of  a  long  runner,  so  that  what  flows  out  below  the 
level  of  the  tap-hole  can  be  broken  up.  This  plan  is 
one  adopted  for  "blowing-out"  as  well  as  "  banking." 
As  will  be  seen  by  Fig.  19,  page  93,  there  are 
often  very  large  bodies  of  metal  below  the  tap  -hole. 
Even  by  the  plan  just  described  these  are  rarely  ever 
all  drained  from  a  furnace,  always  leaving  some  to 
solidify  that  will  have  to  be  brought  back  to  a  liquid 
state  when  the  furnace  is  '  *  blown  in, ' '  requiring  as  a 
general  thing  but  a  few  days. 

The  first  move  in  preparing  to  "bank"  a  furnace  is 
to  discontinue  its  charges  of  ore  and  lime  in  the  regu- 
lar way  and  to  admit  chiefly  fuel,  in  order  to  keep  the 
furnace  filled,  occasionally  dumping  a  little  ore  and 
lime  to  divide  the  fuel  and  to  destroy  the  union  of  a 
solid  combustible  body  of  fuel  and  thereby  assist  in 
smothering  combustion.  As  soon  as  it  is  found  that 
the  last  regular  charge  of  ore,  lime  and  coke  has 
passed  the  level  of  the  tuyeres,  the  furnace  is  tapped 
and  an  extra  pressure  of  blast  applied  so  as  to  force 
out  all  metal  possible.  This  done,  the  blast  is  shut 
off  and  the  ' '  banking  ' '  operation  commenced.  When 
this  is  completed  the  furnace  is  filled  up  with  fuel,  etc. , 
as  above  described,  and  in  some  cases  the  surface  of  the 
last  charge  is  covered  over  with  fine  ore  or  loam  sand 
to  assist  in  shutting  off  draft,  in  which  state  the  fur- 
nace is  left  standing.  As  a  general  thing,  wherever 
sand  can  be  used  for  banking,  it  is  preferable  to  clay, 
as  the  latter  is  apt  to  crack  in  drying  and  leave  crevices 
whereby  air  can  find  access  to  the  fire  to  excite  com- 
bustion. 

In  some  cases  the  fire  may  lie  dormant  in  a  good 
condition  for  six  months  or  more  without  any  renewal 


124  METALLURGY  OF  CAST  IRON. 

of  fuel,  but  this  is  seldom  done.  If,  after  three  or  six 
months  of  banking,  it  is  found  that  conditions  of  trade, 
etc.,  will  not  demand  "blowing  in,"  as  anticipated 
when  first  banking  the  furnace,  the  fires  will  often  be 
allowed  to  die  out,  in  order  to  make  preparations  for 
"shoveling  out,"  so  as  to  discover  if  a  furnace  re- 
quires re-lining  in  parts  or  as  a  whole. 

A  good  illustration  of  the  extent  to  which  banking  a 
furnace  may  be  carried  is  that  conducted  under  the 
able  management  of  Mr.  C.  I.  Rader,  during  the  years 
l893~95,  at  the  Paxto^  Furnace,  Harrisburgh,  Pa. 
Furnace  No.  i  at  tnis  place  was  utuucsd  August,  1893, 
and  not  opened  until  June,  1895,  a  period  of  one  year 
and  ten  months,  at  which  time  the  furnace  was  found 
in  a  condition  to  be  successfully  "  blown  in. "  Mr. 
Rader  says  a  light  ore  burden  and  half  coke  and  an- 
thracite were  used  in  banking  down  the  furnace,  and 
the  top  covered  with  a  layer  of  fine  ore.  This  is  the 
longest  period  of  successful  "banking"  of  which  the 
author  has  any  record. 

When  ««  blowing  in  "  a  "  banked  furnace,"  the  first 
operation  is  to  clean  out  the  tuyere  holes,  etc. ,  of  their 
clay  and  sand  packing,  after  which  the  refuse  and  dead 
ash  in  the  furnace  are  pulled  and  shoveled  out  through 
the  tuyere  openings  and  slag  holes,  so  far  as  possible. 
This  done,  the  tuyeres  are  replaced  and  their  water  and 
blast  connections  completed.  A  heavy  bed  of  fuel  is 
now  charged,  after  which  charges  of  ore,  lime  and  fuel 
are  delivered  into  the  furnace.  The  burden  of  ore 
and  lime  is  gradually  increased  in  weight  in  the  first 
charges  until  several  are  delivered,  when  the  regular 
burden  is  then  charged  on.  The  blast  being  on,  the 
furnace  is  again  in  condition  to  make  iron.  For  the 


"BANKING      FURNACES  AND  CUPOLAS.  125 

first  two  "  casts  "  or  day's  run  a  furnace  is  liable  to 
work  cold,  which  results  in  giving  a  low-grade  metal 
or  iron  high  in  sulphur  and  low  in  silicon.  As  a  gen- 
eral thing,  furnaces  are  compelled  to  use  cold  blast 
when  * '  blowing  in, "  for  the  reason  that  there  is  no 
gas  to  make  the  hot  blast  ovens  operative  until  after  a 
furnace  becomes  sufficiently  heated  to  have  gas  pass 
down  the  "down-comer"  to  the  ovens.  A  few  plants, 
like  that  of  the  Carnegie  Steel  Co.,  having  several 
furnaces  connected  or  in  close  vicinity,  can  bring  hot 
blast  from  other  furnaces  until  the  "blown  in"  furnace 
gets  under  way.  Where  cold  blast  has  to  be  used  at 
the  start,  it  takes  much  longer  to  get  a  high-grade 
iron  than  where  hot  blast  can  be  obtained.  With  hot 
blast  they  may  often,  at  the  very  first  "  cast,"  secure 
high  grade  iron,  whereas  with  cold  blast  it  may  take 
a  dozen  "casts'"  or  more  to  do  so,  and  in  either  case, 
the  largest  output  is  not  generally  obtained  until  a 
furnace  has  been  in  blast  from  one  to  three  months. 

Those  founders  inexperienced  in  furnace  work 
can  well  imagine  from  the  description  here  cited  that 
although  ' '  banking  "  is  a  compromise  to  *  *  blowing 
out, ' '  which  means  a  complete  shut-down,  the  furnace 
manager  is  desirous  of  avoiding  such  manipulations  so 
far  as  possible,  as  the  expense  is  by  no  means  light, 
and  many  sacrifices  will  generally  be  made  in  having 
capital  lying  idle  in  piles  of  pig  iron  in  order  to  run  a 
furnace  steadily,  rather  than  '  *  banking  ' '  to  await  in- 
crease of  orders  or  a  demand  for  their  product.  If 
furnacemen  have  any  assurance  that  they  will  not 
"  blow  in  "  after  three  months'  "  banking,"  they  will 
generally  "blow  out,"  as  the  accumulation  of  ash  and 
dirt  from  a  furnace  banked  to  exceed  three  months 


126  METALLURGY    OF    CAST    IRON. 

is  such  as  to  be  very  apt  to  make  it  difficult  to  get 
a  furnace  working  well  for  a  week  or  more  after  it  is 
"  blown  in." 

Banking  is  generally  done  in  cases  where  a  shut- 
down is  thought  to  be  only  temporary.  If  a  furnace 
"  blows  out,"  which  means  a  clear  shut-down,  nearly 
the  same  amount  of  fuel  and  lime  is  often  charged  to 
follow  the  stock  down  as  if  the  furnace  was  being 
*  *  banked. ' '  This  is  done  so  as  to  burden  the  blast 
and  keep  the  heat  or  flame  of  the  furnace  from  escaping 
and  thus  better  reduce  the  stock  of  ore  to  metal  and 
also  cause  less  heat  to  affect  the  upper  lining  as  well 
as  the  bell  and  hopper  from  melting,  and  makes  a 
cleaner  furnace  when  '  *  shoveled  out. ' '  There  are  a 
few  that  will  *  *  blow  out ' '  a  furnace  without  covering 
the  last  charge  of  ore  well  with  fuel  and  lime,  but 
this  plan  is  not  considered  good  and  safe  furnace 
practice. 

In  "blowing  out"  a  furnace,  the  fuel  used  to  follow 
the  stock  down  can  be  largely  saved,  for  as  soon  as  the 
last  tap  of  iron  is  made,  and  the  blast  shut  off,  the 
tuyeres  P,  Fig.  10,  page  49,  can  be  all  pulled  out  and 
the  incandescent  fuel  raked  out  on  to  the  ground  floor, 
where  with  a  hose,  water  will  soon  dampen  the  fire  in 
the  fuel,  which  will  be  found  to  be  but  little  burned, 
so  that  it  can  be  used  over  again.  After  the  fuel  is 
all  pulled  out  level  with  the  tuyere,  water  can  then  be 
thrown  by  a  hose  to  dampen  the  fire  in  the  hearth,  so 
that  in  six  to  ten  hours  after  the  blast  is  stopped  all 
fire  can  be  extinguished. 

Where  banking  a  cupola  might  be  thought  of,  as  re- 
ferred to  at  the  close  of  this  paper,  it  is  generally  well 
to  have  a  charge  of  fuel  follow  the  last  charge  of  iron, 


"BANKING"   FURNACES  AND  CUPOLAS.  127 

as  this  would  better  assist  closing  off  all  draft  than 
were  the  last  charge  all  iron,  as  a  fine  dust  fuel,  ore, 
etc.,  could  be  used  on  the  surface  to  close  up  all  cavi- 
ties without  calling  for  enough  to  cause  injury,  as 
would  be  the  case  with  fine  stock  used  to  close  up  the 
cavities  between  pieces  of  iron,  instead  of  fuel. 

The  principle  involved  in  "  banking  "  a  furnace  is 
one  that  has  to  a  slight  degree  been  practiced  by  some 
founders,  as  is  seen  in  "American  Foundry  Practice," 
page  301.  The  author  is  so  sanguine  that  the  prin- 
ciples involved  in  banking  are  practical  for  application 
in  cupola  work,  that  he  lately  remodeled  one  of  his 
cupolas  with  a  view  of  experimenting  to  find 
out  how  many  heats  he  could  run  without  drop- 
ping the  bottom.  At  this  writing  conditions  in  our 
shop  work  have  not  permitted  giving  it  a  trial,  the 
reason  for  which  lies  in  the  fact  that  the  cupola  which 
was  prepared  for  this  experiment  was  not  large  enough 
to  run  the  heats  demanded.  The  plans  followed  in  re- 
modeling this  cupola  consist  simply  in  making  all 
tuyere  connections  air-tight,  raising  the  spout  so  as  to 
permit  of  from  two  to  four  inches  of  a  heavier  sand 
bottom,  also  in  providing  a  double  slide  arrangement 
facing  the  tuyere  openings  which,  when  both  were 
closed,  left  a  space  between  them  to  be  filled  with 
loose  sand  that  could  be  readily  removed  by  a  little 
slide  pocket  in  the  bottom  of  the  sand  space.  These 
two  factors,  combined  with  an  arrangement  to  posi- 
tively shut  off  the  admission  of  any  air  where  the 
main  blast-pipe  is  connected  with  the  wind-box,  com- 
pleted the  arrangements.  With  this  device  it  is  the 
intention,  after  the  first  heat  has  been  run  off,  if  not 
a  large  one,  to  thoroughly  melt  down  any  iron  that 


128  METALLURGY    OF    CAST    IRON. 

may  be  in  the  cupola,  after  which  the  breast  will  be 
opened  and  all  dead  ash  and  refuse  lying  in  the 
4 'bed"  will  be  raked  out.  After  all  dead  material  has 
been  thus  cleaned  out,  the  breast  will  be  firmly  sealed 
up  with  tightly  rammed  sand,  and  all  tuyere  connec- 
tions, etc. ,  closed  as  above  described.  A  little  extra  fuel 
being  now  put  in  and  the  top  charging  door  closely 
sealed,  the  cupola  will  be  allowed  to  stand  in  this  con- 
dition until  time  to  charge  for  the  next  heat,  when  the 
"bed"  will  be  "  replenished,"  the  cupola  re-charged, 
and,  after  the  breast  has  been  replaced,  the  heat  pro- 
ceeded with  as  usual.  How  many  times  this  opera- 
tion can  be  repeated  without  *  *  dropping  the  bottom  '  I 
can  only  be  told  by  practice.  In  endeavoring  to  follow 
such  a  practice  the  management  of  the  cupola  must  be 
in  intelligent  hands,  as  it  can  be  readily  seen  that  to 
charge  a  cupola  ignorantly  or  carelessly,  as  is  often 
done,  would  result  in  leaving  iron  at  a  level  with  the 
tuyeres,  or  all  on  one  side  of  the  cupola,  so  that  it 
could  not  be  melted  at  the  end  of  a  heat.  These  ideas 
are  not  presented  with  the  expectation  that  all  found- 
ers are  going  to  drop  their  present  methods  to  adopt 
the  plans  outlined ;  they  are  simply  offered  as  sugges- 
tions to  evolve  ideas  which  may  favor,  the  inauguration 
of  new  practices  that  to-day  might  seem  absurd  and 
impracticable. 

John  C.  Knoeppel,  of  the  Buffalo  Forge  Co.,  Buf- 
falo, N.  Y.,  recently  related  to  the  author  an  experi- 
ence in  banking  a  cupola,  which  may  often  prove  of 
benefit.  In  brief  it  is  as  follows :  The  blast  had  just 
been  started  and  the  iron  was  not  yet  down,  when  an 
accident  occurred  to  the  machinery,  stopping  the 
blast.  As  the  damage  could  not  be  repaired  within 


"  BANKING         FURNACES    AND    CUPOLAS.  129 

the  lapse  of  many  hours,  Mr.  Knoeppel  simply  closed 
all  air  openings  tightly  with  clay  and  sand,  and  cov- 
ered the  top  of  the  stock  at  the  charging  door  with 
fine  dust  coke.  When  the  blast  was  started,  about 
sixteen  hours  after  the  shut-down,  the  melting  went 
on  in  good  shape,  as  in  the  usual  practice.  This  was 
done  in  a  cupola  of  about  56  inches  inside  diameter. 
One  factor  assisting  to  make  Mr.  Knoeppel' s  plan  so 
successful  was  the  fact  of  the  iron  not  having  started 
to  melt  when  the  break-down  occurred.  Mr.  Knoep- 
pel's  experience,  combined  with  that  recited  by  the 
author  in  "American  Foundry  Practice, "  above  noted, 
may  suggest  expedients  which  may  often  be  profitably 
adopted. 


CHAPTER  XVII. 

CONSTANT    AND   CHANGEABLE    METAL- 
LOIDS IN  MAKING  IRON. 

If,  in  making  iron,  all  the  metalloids  remained  fairly 
constant,  not  varying  in  their  percentage  one  cast 
from  another,  we  could  obtain  a  uniform  product  and 
have  no  such  thing  as  different  grades  of  iron  from  like 
mixtures  of  ore,  fuel,  and  flux.  But  this  condition 
does  not  exist ;  instead,  we  find  that  a  furnace,  at  the 
present  state  of  advancement,  seldom  makes  two  casts 
of  iron  exactly  alike  in  analysis  or  grade  from  the 
same  mixtures  of  like  ores,  fuels,  and  fluxes.  The 
elements  that  vary  the  most  and  effect  the  greatest 
change  in  the  grade  or  the  carbons  of  iron  are  silicon 
and  sulphur.  A  furnaceman  can  be  most  particular 
and  have  all  conditions  alike  as  far  as  lies  in  his  power, 
but  for  all  this  he  may  have  some  casts  which  will 
differ  widely  in  silicon  and  sulphur  contents,  espe- 
cially when  making  iron  over  1.50  silicon  and  in  all 
grades  during  very  hot  weather.  It  is  true  there  will 
be  changes  in  the  total  carbon,  manganese,  and  phos- 
phorus, but  these  rarely  cause  radical  changes  in  the 
grade  of  an  iron  coming  from  like  mixtures.  Some 
experiences  on  this  latter  point  are  related  in  Chapter 
XVIII.,  page  136.  It  is  to  be  remembered  that  the 
author  is  not  claiming  that  manganese  and  phosphorus 


CONSTANT    AND    CHANGEABLE    METALLOIDS,   ETC.       131 

cannot  effect  a  change  in  the  grade  of  an  iron.  Varia- 
tions of  either  of  these  two  elements  can  change  the 
grade  similar  as  variations  in  silicon  or  sulphur,  but  we 
must  look  to  the  furnaceman  in  preparing  his  mixtures 
of  ores,  etc. ,  when  making  iron.  If  he  desires  an  iron 
high,  medium,  or  low  in  manganese  or  phosphorus,  he 
can  generally  obtain  it  so  evenly,  in  iron  below  3.00 
per  cent,  silicon,  as  not  to  affect  in  a  practical  way  the 
grade  of  the  iron  which  he  desires  to  obtain,  as  long 
as  the  furnace  uses  the  same  ores,  fuel,  and  fluxes. 
On  the  other  hand,  the  silicon  and  sulphur  may  vary 
considerably  at  times.  However,  future  advancement 
in  obtaining  more  uniform  temperatures  and  distri- 
bution of  blast  in  a  furnace,  which  is  now  being  grad- 
ually secured  by  some,  will  bring  about  improvement 
in  this  line.  Nevertheless,  silicon  and  sulphur  will 
always  be  the  metalloids  which  will  most  largely 
change  the  grade  of  iron  to  a  greater  or  less  degree 
where  the  same  ores,  fluxes,  and  fuels  are  used. 

Changes  in  the  total  carbon.  It  is  thought  by  some 
furnacemen  that  the  higher  the  temperature,  and  the 
more  slowly  the  ore  passes  down  in  its  reduction  to 
iron,  to  the  hearth  of  a  furnace,  the  greater  total  carbon 
will  be  found  in  like  irons.  However,  the  author  has 
failed  to  find  where  there  were  changes  in  total  carbon, 
by  the  use  of  the  same  ores,  etc.,  sufficient  to  radically 
change  the  grade  of  iron. 

Ores  from  the  same  mines  or  locality  are  liable  to 
differ  in  their  composition  sufficiently  to  occasionally 
change  the  percentage  of  manganese  and  phosphorus, 
to  some  extent,  in  the  same  brand  of  iron.  Never- 
theless, such  changes  would  generally  call  for  an 
alteration  of  about  half  of  one  per  cent,  in  manganese 


132  METALLURGY    OF    CAST    IRON. 

or  one-fifth  to  one-third  per  cent,  of  phosphorus  to 
change  the  grade,  similar  as  the  alteration  of  one- 
quarter  of  one  per  cent,  in  silicon  would  do.  The 
author  believes  that  furnacemen  will  agree  that  it 
would  be  very  rare  to  have  such  a  variation  as  above 
in  manganese  and  phosphorus,  in  irons  made  from  ore 
that  comes  from  one  mine  or  locality.  As  there  is  a 
liability,  on  rare  occasions,  of  manganese  and  phos- 
phorus varying  to  an  effective  degree  from  similar 
ores,  and  then  again  a  change  in  the  total  carbon  to 
alter  the  grade  of  an  iron,  it  may  often  pay  those  who 
are  manufacturing  castings,  where  such  changes  as 
above  would  seriously  affect  their  iron,  to  always  have 
an  analysis  of  the  total  carbon,  manganese,  and  phos- 
phorus in  connection  with  the  silicon  and  sulphur. 
There  is  one  thing  to  be  remembered  and  that  is,  that 
a  furnaceman  has  far  less  difficulty  in  obtaining  a 
uniform  grade  when  making  low  silicon  irons,  or  that 
under  1.50,  than  above  this  percentage;  and  also  that 
there  is  much  more  difficulty  in  obtaining  a  uniform 
grade  in  very  hot  weather,  due  to  humidity  of  the  air, 
than  when  the  thermometer  is  below  85  degrees  F. 
More  on  this  point  is  seen  in  Chapters  X.  and  XLV., 
pages  78  and  306.  Furnacemen  are  finding  that  if 
they  are  not  called  upon  to  increase  temperatures  of 
blast  over  1,000  degrees  F.  (some  find  it  best  to  keep 
between  850  to  900  degrees  F.),  and  have  a  good  uni- 
form distribution  of  the  blast,  they  can  secure  a 
more  uniform  product  than  otherwise.  Largely  for 
^these  reasons  furnacemen  prefer  to  run  on  low  silicon 
iron. 

One  is  most  impressed  with  the  uncertainty  of  fur- 
nace workings  when  in  urgent  need  of  ten  hundred 


CONSTANT    AND    CHANGEABLE    METALLOIDS,   ETC.       133 

tons  or  more  of  any  certain  grade  of  iron  over  1.50  in 
silicon  from  a  furnace  that  is  trying  to  make  it,  and  no 
stock  of  iron  in  that  special  furnace  yard  to  draw  from. 
Anybody  placed  in  this  position  might  soon  be 
forced  to  realize  by  reason  of  waiting  for  the  ship- 
ments they  desired,  that  furnacemen  cannot,  as  yet, 
always  perfectly  control  a  furnace  to  obtain  the  grade 
they  desire  at  every  cast. 


CHAPTER  XVIII. 

SEGREGATION    OF    IRON    AT    FURNACE 

AND  FOUNDRY. 

We  often  find  a  segregation  of  metalloids  in  pig  iron, 

but  rarely,  if  ever,  in  re-melted  iron  or  castings. 
One  peculiarity  in  this  respect  lies  in  the  difference 
often  found  in  the  upper  cast  body  or  face  of  pig  iron 
containing  the  highest  sulphur,  as  shown  by  the  fol- 
lowing four  samples,  Table  18: 

TABLE   1 8. —  SEGREGATION  OF  SULPHUR  IN  PIG  IRON. 


No.  i. 

No.  2. 

No.  3. 

No.  4. 

Too 

.117 

•  115 

.084 

.OSS 

Bottom       

.083 

.094 

.070 

.047 

The  above  analysis  shows  that  "  direct  metal,"  or 
iron  coming  from  a  blast  furnace,  tends  to  favor  the 
escape  of  sulphur,  but  that  owing  to  the  top  surface 
of  the  pig  chilling  so  as  to  form  a  crust  at  an  early 
stage  of  the  solidification  of  the  metal  in  the  pig  beds, 
the  sulphur  in  rising  to  escape  was  caught  and  hence 
the  higher  sulphur  found  in  the  top  body  of  the  pig, 
as  shown. 

Silicon  also  segregates  in  pig  metal.  Wherever  pig 
iron  shows  soft  gray  spots,  analysis  will  generally 
show  these  to  be  higher  in  silicon  than  the  sur- 
rounding metal.  Then  again,  it  has  been  found  that 
the  first  metal  from  a  furnace  is  generally  lower  in 
silicon  than  that  which  flows  afterward,  in  a  manner 
often  so  uniform  as  to  show  that  there  is  a  gradual 


SEGREGATION    AT    FURNACE    AND     FOUNDRY.  135 

increase  of  silicon  in  the  metal  from  the  bottom  up- 
wards as  it  lies  in  a  furnace  before  being  tapped. 

Variations  in  the  working  of  a  furnace  make  a  rad- 
ical difference  in  diffusion  of  the  metalloids  silicon  and 
sulphur,  as  can  be  seen  by  the  following  analyses, 
which  the  writer  has  also  secured  for  this  work  through 
the  courtesy  of  Mr.  C.  C.  Jones,  an  able,  experienced 
furnace  manager,  operating  two  furnaces  at  Sharps- 
ville,  Pa.  The  pig  beds  are  numbered  in  the  following 
Table  19  according  as  they  were  cast,  No.  i  being  that 
farthest  from  the  furnace,  receiving  the  first  iron  and 
No.  6  the  last: 

TABLE   19. — ANALYSES    OF    PIG   BEDS    IN    A    CHANGEABLE    FURNACE. 


i 

2 

3 

4 

5 

6 

Silicon  

.60 
.084 

.68 
.071 

.70 
.062 

1.  00 
.050 

1.25 
.042 

2.20 

.027 

Sulphur 

With  the  furnace  normal  the  result  was  as  follows  : 

Silicon  

2.18 

.021 

2.18 

.021 

2.22 
.023 

2.23 
.019 

2.25 
.019 

2.25 
.OI9 

Sulphur 

The  above  analyses  of  the  normal  working  of  a  fur- 
nace present  the  best  uniform  distribution  of  silicon 
and  sulphur  which  has  come  under  the  writer's  notice. 
As  this  is  a  question  of  no  little  importance  to  the 
founder,  attention  is  called  to  Table  No.  20,  on  next 
page,  showing  the  analyses  of  eight  (8)  different  "casts" 
giving  the  silicon  contents  from  the  bottom  upward, 
subscribed  by  Mr.  H.  Rubricius  in  Chemiken  Zeitung 
and  the  Journal  of  the  Iron  and  Steel  Institute,  No.  <?, 

l894- 

The  exhibits  treat  only  of  silicon  and  sulphur. 
With  regard  to  the  segregation,  etc.,  of  phosphorus 
and  manganese,  the  only  experiments  which  the  writer 
has  observed  are  those  by  Mr.  A.  P.  Bjerregaard,  com- 


i36 


METALLURGY    OF    CAST    IRON. 


mented  upon  in  the  Iron  Age,  November  30,  1895.  He 
states  his  conclusions  as  follows:  "There  is  often  a 
slight  variation  in  the  amount  of  phosphorus  and  man- 
ganese in  the  different  grades  formed  in  the  same 
*  cast, '  but  so  far,  no  regular  occurring  progression 
variation  has  been  observed.  At  best,  the  difference 
is  only  a  few  hundredths  of  one  per  cent. ' '  The  author 
could  present  several  more  tables  showing  uneven  dis- 
tribution of  silicon,  etc.,  but  those  shown  are  sufficient 
to  illustrate  the  necessity  for  reform  in  the  lines  advo- 
cated by  the  author. 

When  the  founder  considers  that  a  difference  of  one- 

TABLE    2O. — SILICON    ANALYSES    OF    EIGHT    CASTS. 


Test  of  pig  iron. 

1 

*v> 

2d  bed. 

1 
* 

1 

£ 

^5- 

i 

& 
v> 

1 

A 
to 

T3 

i 

jja 

"£. 

i  cast  

.13 

i  15 

I>15 

I.IQ 

!.•»•* 

1.40 

42 

•M 

i  44 

i  45 

I  60 

163 

I  72 

79 

3  cast  

.15 

i-34 

1-43 

1.57 

2  17 

2.l8 

20 

I  29 

I  SO 

J-54 

1.66 

1.82 

1.84 

88 

1.95 

2.09 

2.13 

2.45 

2  7O 

2.72 

.76 

6  cast               

1.83 

1.84 

1.86 

1.89 

2.16 

2  2O 

2  72 

2  74 

2  77 

2  79 

2  8s 

2  88 

2  8q 

8  cast            

2.46 

2.48 

2.50 

2.53 

2-54 

2.58 

2.6o 

quarter  of  one  per  cent,  in  silicon  and  a  few  hundredths 
of  one  per  cent,  in  sulphur  will  seriously  alter  the 
"grade"  of  his  mixture  so  as  to  either  make  his  "cast" 
too  soft  or  too  hard,  and  may  often  cause  him  great 
trouble  or  loss  in  the  castings  produced,  he  should  at 
once  perceive  that  the  uneven  distribution  of  silicon 
and  sulphur  which  occurs  more  or  less  in  every  "cast" 
of  a  furnace  is  a  quality  seriously  affecting  his  inter- 
ests. Especially  is  this  so,  when  he  is  aware  that  the 
one  analysis  which  may  be  given  is  simply  an  average 
of  the  whole,  generally  taken  from  the  two  ends  and 


SEGREGATION  OF  IRON  AT  FURNACE  AND  FOUNDRY.     137 

middle  of  a  "  cast,"  and  that  a  car  of  iron  may  come 
to  him  from  a  "  cast  "  having  one  portion  from  one- 
half  to  one  per  cent,  higher  in  silicon  than  another. 
This  is  fully  verified  by  Mr.  Rubricius's  table  which 
shows  that  the  two  ends  of  a  "  cast ' '  may  vary  one  per 
cent,  in  silicon.  Mr.  Rubricitis  also  states  that  "  not- 
withstanding the  large  number  of  experiments  made, 
it  was  not  possible  to  correlate  the  initial  percentage  of 
silicon  and  the  rate  of  increase,  as  iron  poor  in  silicon 
presents,  in  some  cases,  a  large  increase  in  silicon  in 
the  upper  parts.  This  can  only  be  due  to  the  differ- 
ence in  specific  gravity  between  silicon  and  iron. ' ' 
.  The  uneven  distribution  of  silicon  and  sulphur  in 
pig  metal  is  largely  due  to  conditions  over  which 
furnace  managers  have,  as  a  rule,  not  perfect  con- 
trol, while  with  castings  the  moulder  or  founder  can, 
at  will  or  through  methods  in  casting,  give  rise  to  an 
ill  diffusion  of  the  carbons  that  could  often  be  pre- 
vented were  he  only  aware  of  the  conditions  which 
effect  such  results  in  castings.  The  moulder  when 
turning  out  a  casting  having  hard  or  soft  spots  often 
finds  the  word  * '  segregation  ' '  very  convenient  to 
disguise  evil  effects  of  hard  ramming,  wet  sands,  or 
ill-vented  moulds.  When  a  mould  has  been  properly 
made  and  the  iron  well  mixed  and  melted  hot  and 
poured  as  it  should  be,  there  is  generally  little  to  fear,  in 
i  practical  way,  from  segregation  in  castings  that  can 
oe  charged  to  the  iron,  aside  from  what  effects  degrees 
in  cooling  or  casting  in  a  chill  can  have  in  causing 
different  proportions  of  combined  or  graphitic  carbon 
A  rammer  should  never  be  allowed  to  hit  a  pattern,  as 
this  causes  a  hard  spot  on  the  mould  which,  in  light 
castings,  can  change  the  character  of  the  carbons  or 


138  METALLURGY    OF    CAST    IRON. 

the  iron  at  that  spot.  And  the  same  is  to  be  said  where 
the  swab  or  ill  ' '  tempered  ' '  sand  causes  one  spot  or 
portion  of  the  mould  to  be  different  from  another,  or 
the  venting1  is  inadequate  for  the  free  escape  of  gas  or 
steam.  Hard  grades  of  iron  are  more  liable  to  an  ill 
/diffusion  of  the  carbons  than  soft  grades,  especially  so 
where  the  former  is  melted  or  poured  dull.  Light 
castings  are  also  much  more  liable  to  an  ill  diffusion  of 
the  state  of  the  carbon  than  heavy  castings.  The 
above  statements  also  give  additional  reasons  why  test 
bars  as  small  as  one -half  inch  square,  or  any  having 
square  corners,  are  not  the  best  standards  for  making 
comparison  of  mixtures,  etc. 

By  re-melting  pig  iron  we  effect  a  mixing  process  in 
which  the  chemical  constituents  of  the  castings  will  be 
uniform  unless  they  are  distorted  by  means  of  dull 
iron,  hard  ramming,  wet  sands,  ill  venting,  or '  *  chills, ' ' 
as  above  stated.  The  metalloids  most  liable  to  segre- 
gate are  the  carbons  and  silicon.  Chiefly  with  the  first 
named  lie  most  of  the  phenomena  which  effect  segrega- 
tion in  castings,  and  which  are  defined  simply  by  one 
part  being  higher  in  graphitic  or  combined  carbon  than 
another.  Some  have  claimed  the  existence  of ' '  sulphur 
spots  ' '  in  castings.  With  iron  melted  or  poured  dull 
these  may  exist,  but  with  the  reverse  conditions  the 
writer  has  reason  to  believe,  from  analyses  which  he 
has  conducted,  that  sulphur  will  generally  be  found 
uniformly  distributed  throughout  a  casting  that  has 
not  blown  or  from  any  cause  been  chilled. 


CHAPTER  XIX. 

MIXING    CASTS    OF    PIG    IRON    AT    FUR- 
NACE  AND  FOUNDRY. 

A  difference  of  one  per  cent,  in  silicon  which  can 
exist  between  the  ends  of  a  cast  of  pig  iron,  as  shown 
in  the  last  chapter,  should  cause  any  thoughtful  person 
to  perceive  the  wisdom  of  thoroughly  mixing  a  furnace 
cast  or  pile  of  iron  before  it  is  charged  into  a  cupola. 
This  is  where  the  most  uniform  results  in  obtaining  an 
even  grade  of  iron  are  desired  in  any  special  line  of 
castings.  As  an  example,  if  an  ill-mixed  cast  of  pig 
averaging  2.00  per  cent,  in  silicon,  with  its  extreme 
ends  varying  i .  oo  in  silicon,  was  charged  without  being 
mixed,  one  part  of  the  iron  charged  would  contain  but 
1.50  of  silicon  while  the  other  portion  would  contain 
2.50  silicon.  It  is  impossible  to  expect  uniform  results 
in  castings  from  such  an  ill -mixed  cast  or  pile  of  iron. 
vSome  foundrymen,  when  first  adopting  chemistry  in 
making  mixtures  of  iron,  have  had  just  such  experiences 
as  the  above,  but,  not  knowing,  it  condemned  the  princi- 
ple of  working  by  analysis,  when,  in  truth,  it  was  not 
chemistry  that  was  at  fault,  but  the  evils  of  ill-mixing 
or  ill-diffusion  of  the  silicon  in  a  cast  or  pile  of  iron 
and  no  attention  having  been  paid  to  the  question  of 
mixing  it  thoroughly  before  it  was  charged  into  the 
cupola.  The  founder  adopting  chemistry  must  have 


140  METALLURGY    OF    CAST    IRON. 

his  practice  based  upon  correct  principles,  or  he  cannot 
expect  the  results  he  desires  in  making  mixtures  of 
iron.  An  ill-mixed  cast  of  pig  iron  can,  generally, 
mislead  any  founder  in  determining  the  cause  of  fail- 
ure to  obtain  the  grade  of  iron  he  felt  so  confident  of 
securing. 

A  thorough  mixing  of  a  cast  of  pig  iron  is  not  a  diffi- 
cult task ;  it  requires  but  a  recognition  of  its  necessity, 
and  means  can  be  readily  devised  to  accomplish  the 
end.  One  plan,  practicable  of  adoption  by  most 
furnaces,  would  be  when  loading  cars  for  shipment  to 
consumers  to  have  every  other  buggy  load,  or  pig  if 
handled  by  men,  placed  at  the  opposite  ends  of  the  car. 
When  the  foundryman  unloads  the  car  he  should  follow 
the  plan  pursued  in  loading,  which  means  to  take  a 
pig  from  each  end  of  the  car  alternately  and  load  onto 
buggies  or  in  piles.  By  such  a  method  a  cast  or  car  of 
iron  should  be  pretty  well  mixed  by  the  time  it  was 
charged  into  a  cupola. 

Where  a  founder  has  yard  room,  a  good  plan  is  to 
load  several  cars  of  the  iron  closely  alike  in  analysis, 
or  for  one  mixture,  on  top  of  each  other  in  a  long  pile, 
being  careful  to  have  each  car  load  distributed  evenly 
in  height  the  whole  length  of  the  pile,  and  in  taking 
the  iron  from  the  car  take  a  pig  from  each  end  alter- 
nately as  near  as  practicable.  A  pile  of  any  certain 
grade  or  brand  of  this  character  can  be  made  to  hold 
six  or  more  cars  of  iron,  and  then  when  using  the  iron 
from  the  piles  it  is  taken  from  the  two  ends  as 
uniformly  as  practicable.  A  little  study  of  this  method 
will  show  that  drillings  taken  from  four  to  six  pieces 
of  pig,  pulled  from  a  fair  division  of  the  two  ends 
would,  when  thoroughly  mixed  and  analyzed,  give  an 


MIXING    CASTS    OF    PIG    IRON    AT    FURNACE,   ETC.        14! 

analysis  that  would  be  a  very  close  estimate  of  the 

silicon  or  other    metalloids  to   be   found  in  any  such 

body  of  iron  in  that  special  grade,  brand,  or  pile  of  iron. 

Very  often  the  founder  has  not  room  to  pile  iron,  or 

is  compelled  to  use  it  direct  from  cars  or  small  piles 
already  in  his  yard.  In  such  cases  the  different  casts, 
or  parts  of  such,  could,  after  being  mixed  in  loading  it 
on  buggies  as  described,  be  conveyed  to  the  cupola 
stage  and  stacked  in  distinct  piles  according  to  varia- 
tions that  exist  in  the  percentages  of  silicon,  etc. 
When  charging  the  iron  that  amount  necessary  to 
make  a  mixture  would  be  taken  from  the  different  piles 
in  an  alternate  manner;  this  would  insure  a  good 
mixing  of  the  grades  as  they  lay  in  the  cupola.  For 
an  example,  if  an  average  of  1.90  in  silicon  was  desired 
in  a  mixture,  and  the  only  iron  that  could  be  obtained 
were  casts  or  piles  containing  1.60  and  2.20  silicon, 
with  sulphur  about  uniform,  then  each  pile  would  be 
piled  separately  on  the  -cupola  stage  and  a  pig  taken 
from  each  pile  alternately  when  charging  the  cupola. 
This  is  a  plan  which  works  well,  providing  a  trusty 
man  is  in  control  of  the  charging.  If  such  is  not  in 
command,  there  are  times  when  this  practice  leaves  a 
chance  for  error.  Such  can  be  brought  about  by  new 
men,  or  old  ones,  making  errors  in  sorting  or  placing 
the  iron  on  the  staging  or  in  charging  it  into  the 
cupola. 

A  plan  which  avoids  risks,  wherever  two  or  more 
grades  must  be  used  to  obtain  the  average  desired,  as 
described  in  the  last  paragraph,  is  to  have  different 
brands  or  grades  go  to  the  stage  at  the  same  time  on 
independent  buggies,  and  then  instead  of  piling  each 
grade  separately  as  is  done  in  the  above  plan,  they  are 


142  METALLURGY    OF    CAST    IRON. 

mixed,  pig  about,  in  the  same  pile  of  ten  hundred  to  a 
ton  each,  so  that  when  charging  time  comes  there  are 
no  distinct  iron  piles  of  high  and  low  silicon  to  make  a 
mixture 'of,  which  must  be  carefully  guarded  in  order 
that  no  more  of  one  than  another,  as  desired,  goes  into 
the  cupola;  but  it  allows  any  pile  to  be  used,  and  if 
the  men  are  careless  and  make  blunders  they  can  do 
no  harm,  as  with  the  former  plan.  This  latter  method 
involves  no  more  labor  in  piling  the  iron  on  a  cupola 
stage  than  the  former  and  is  superior  in  giving  a 
uniform  mixture,  if  stage  room  will  permit  of  such  a 
practice. 

The  gradual  introduction  of  sandless  pig,  cast  from 
ladles,  is  a  step  which  will  greatly  help  in  giving  the 
founder  uniform  casts  of  pig  iron,  as  first  catching  the 
metal  in  large  ladles  before  pouring  the  pig  moulds 
cannot  but  act  as  a  mixer  and  cause  the  one  ladle  or 
cast  of  pigs  to  be  more  uniform  in  their  chemical  com- 
position than  is  possible  by  casting  them  in  sand 
moulds,  after  the  old  method.  By  this  plan  each 
ladle's  cast  of  pig  could  be  analyzed.  This  would  give 
positive  assurance  of  obtaining  certain  bodies  of  iron 
that  would  be  uniform  in  analysis,  without  having  to 
resort  to  mixing  each  cast  of  iron.  These  are  all 
factors  which  strongly  recommend  the  use  of  sandless 
pig  iron.  For  methods  of  calculating  percentages  of 
silicon,  sulphur,  etc.,  as  found  in  iron,  to  obtain  aver- 
ages for  making  mixtures,  see  Chapter  XXXVI. 

Another  evil  practice,  aside  from  ill-mixing  of  sand 
cast  pig  iron,  is  the  practice  which  some  furnacemen 
making  foundry  iron  have  followed  of  only  taking  one 
analysis  of  one  of  the  four  to  five  casts  a  furnace  may 
make  during  twenty-four  hours,  and  letting  the 


MIXING    CASTS    OF    PIG    IRON    AT    FURNACE,   ETC.        143 

analysis  of  that  one  cast  stand  for  the  chemical  prop- 
erties of  the  four  or  five  casts  which  the  furnace  has 
made  that  day.  It  is  not  to  be  understood  that  many 
furnaces  follow  this  practice.  However,  such  a  prac- 
tice should  not  be  tolerated  by  any  furnace  claiming 
to  grade  iron  by  analysis,  and  is  little  better  than 
trying  to  achieve  desired  results  in  re-melting  by 
judging  the  grade  of  pig  iron  by  its  fracture  or  hard- 
ness. Every  furnace  cast  should  be  analyzed  and  the 
metal  of  each  cast  kept  separate  when  piled  in  the  yard 
or  shipped  on  cars,  so  that  when  the  founder  receives 
the  iron  he  has  not,  in  connection  with  an  ill-mixed 
cast  of  iron,  a  chemical  guess,  but  a  true  analysis  to 
guide  him  aright  in  re-melting  his  pig  iron.  Give  the 
founder  a  true  analysis  of  a  well  sampled  cast  of  pig 
iron,  in  connection  with  having  it  well  mixed,  or  cast 
from  one  ladle,  as  in  sandless  pig,  before  the  pig  iron 
is  charged  into  a  cupola,  and  he  will  find  that  chem- 
istry is  a  guide  that  can  be  relied  upon  in  assisting 
him  to  obtain  the  grades  of  iron  he  desires  in  his 
castings. 


CHAPTER  XX. 

DIFFERENT    KINDS    OF    PIG   IRON    USED 

AND  DEFINITION  OF  BRAND  AND 

GRADE. 

The  brand  of  an  iron  refers  to  some  characteristics 
peculiar  to  itself  or  distinct  from  what  can  be  found  in 
some  other  irons;  as,  for  example,  in  the  difference 
found  between  charcoal  and  coke  iron,  and  often  made 
by  the  use  of  different  ores  and  fluxes,  although  the 
same  fuel  may  be  used. 

The  grade  of  an  iron  refers  to  the  different  degrees 
of  hardness,  strength,  or  contraction  and  chill  which 
may  be  obtained  from  any  special  brand  of  iron.  In 
a  general  way  high  silicon  or  soft  irons  are  called  high 
grade  irons,  and  low  silicon  or  hard  irons  low  grades. 
It  has  been  claimed  that  the  amount  of  silicon  in  pig 
iron,  and  which  element  chiefly  regulates  the  grade, 
could  be  told  by  the  contraction  of  test  bars.  This  is 
impractical.  The  only  sensible  way  to  define  the  silicon 
or  any  other  metalloid  contents  of  any  test  bar  or  cast- 
ing is  by  chemical  analysis.  The  contraction  merely 
assists  in  defining  the  grade  of  iron  and  nothing  more. 

Grading  pig  iron  should  mean  sorting  it  into  cars  or 
piles,  according  to  the  degree  of  strength  or  hardness 
thought  obtainable  from  it  when  re-melted  to  make 
castings.  A  few  years  back  every  furnace  had  its 
*  *  graders, ' '  whose  special  business  it  was  to  separate 


DIFFERENT    KINDS    OF    PIG    IRON,    ETC.  145 

the  casts  of  iron  into  different  piles,  according  to  the 
grade  of  the  pig  iron  by  fracture.  The  most  open  pigs 
went  into  piles  as  a  No.  i  iron,  the  smaller  grained  as 
Nos.  2,  3,  and  4  and  upward,  according  as  the  grain 
decreased  in  size.  The  greatest  care  was  exercised  in 
thus  grading  iron,  not  only  because  it  was  believed  that 
the  size  of  the  grain  revealed  the  grade,  but  also 
because  the  ' '  grader  ' '  had  a  reputation  to  sustain  in 
making  his  various  piles  of  even  grain,  and  the  furnace- 
man  was  anxious  to  have  every  piece  of  the  open 
grained  iron  collected  by  itself ;  for  No.  i  iron  brought 
him  more  money  than  a  No.  2.  With  the  advent  of 
selling  by  chemical  analysis  all  this  was  changed. 
The  graders  were  replaced  by  the  chemists,  and  the 
iron  as  it  comes  from  a  furnace  cast  is  now  thrown  into 
one  pile  or  car,  and  neither  furnaceman  nor  progressive 
founder  as  a  rule  pays  any  attention  to  the  color  or  the 
size  of  the  grain  of  iron  in  the  pig.  The  different 
brands  are  now  generally  piled,  by  progressive  furnace- 
men,  according  to  the  percentage  of  silicon  and  sulphur 
the  iron  contains,  as  they  now  concede  these  to  be  the 
elements  or  metalloids  that  vary  the  grade  of  any  iron 
made  from  like  ores,  fuel,  and  fluxes  —  a  system 
which  was  advocated  by  the  author  in  earlier  writings, 
and  the  first  edition  of  this  work. 

The  different  brands  of  pig  iron  are  classed  as  foun- 
dry, charcoal,  bessemer,  gray  forge,  basic,  silvery  or 
ferro-silicon,  mottled,  and  white  iron. 

Foundry  iron  is  made  with  coke  or  anthracite  fuel. 
Its  silicon  generally  ranges  from  i.oo  to  4.00,  sulphur 
.01  to  .05,  manganese  from  a  trace  to  1.50,  phosphorus 
from  .20  to  1.50,  and  is  a  class  of  iron  used  in  the 
construction  of  chilled  as  well  as  unchilled  castings. 


146  METALLURGY    OF    CAST    IRON. 

Charcoal  iron  is  made  with  charcoal  fuel.  Its  silicon 
generally  ranges  from  .50  to  2.00,  although  it  is  made 
with  silicon  as  high  as  5 .  oo  per  cent.  The  sulphur  ranges 
from  a  trace  up  to  .08,  manganese  from  a  trace  to  1.50, 
phosphorus  .15  to  .75.  On  the  whole  it  can  be  made 
richer  in  iron  and  poorer  in  silicon,  phosphorus,  and 
sulphur  than  a  coke  or  anthracite  iron.  It  is  chiefly 
used  for  the  manufacture  of  such  castings  as  guns  and 
chilled  work,  and  for  which  it  can  excel  all  other 
brands  of  iron  when  melted  in  an  air  furnace. 

Bessemer  is  made  with  coke  and  anthracite  fuel. 
Its  silicon  ranges  from  .75  to  2.50,  sulphur  .01  to  .05, 
manganese  .20  to  i.oo,  with  phosphorus  under  .10.  If 
it  exceeds  .10  phosphorus,  it  is  then  called  "  off -Besse- 
mer ' '  and  may  be  used  as  a  Foundry  iron.  This  pig 
metal  is  chiefly  used  at  steel  works  for  making  steel 
and  in  foundries  for  ingot  moulds,  and  can  often  be 
well  used  in  the  place  of  ' '  foundry  iron  ' '  in  general 
castings  not  requiring  good  or  extra  fluid  metal  to  run 
them. 

Gray  forge  iron  is  a  metal  of  gray  fracture  with  little 
or  no  grain,  ranging  from  .50  to  2.00  silicon  and  from 
.03  to  .20  in  sulphur  and  which  is  usually  high,  with 
low  silicon.  Its  manganese  and  phosphorus  can  range 
as  found  in  general  iron.  This  brand  of  iron  is  chiefly 
used  as  mill  iron  in  puddling  furnaces  producing 
wrought  iron,  and  also  for  the  manufacture  of  water 
pipes,  etc. ,  often  being  mixed  with  higher  silicon  irons. 

Basic  iron  is  of  a  similar  character  as  gray  forge, 
only  its  sulphur  should  not  exceed  .05,  and  is  generally 
desired  to  be  low  in  phosphorus,  although  it  may  range 
from  .20  to  2.50.  Its  silicon  is  generally  desired  under 
i.oo,  and  manganese  may  range  from  .30  to  i.oo  or 


DIFFERENT    KINDS    OF    PIG    IRON,     ETC.  147   t 

higher.  This  brand  of  iron  is  cast  in  chill  molds  or 
magnesia  sand  and  is  used  chiefly  in  the  basic  open- 
hearth  furnace  to  make  steel. 

Silvery  or  ferro-silicon  iron  is  sometimes  made  with 
all  coke,  and  then  again  with  coal  and  coke.  The 
silicon  ranges  from  6.00  to  1 6.0*0.  It  is  derived  from 
high  silicious  ores  and  excessive  fuel  to  give  high 
temperatures  in  the  furnace. 

Mottled  and  white  iron  is  made  with  both  coke, 
anthracite,  and  charcoal  fuels.  Its  silicon  ranges  from 
.10  to  i. oo,  sulphur  from  .05  to  .30,  manganese  .10  to 
1.50  or  over,  phosphorus  .03  to  .50  and  upward,  and 
usually  high  in  carbon.  These  irons  are  generally  the 
off  product  of  a  furnace  that  has  not  been  working 
well,  and  are  used  for  hard  or  chilled  castings,  or  at 
rolling  mills  to  be  mixed  with  gray  forge  irons. 


CHAPTER  XXI. 

GRADING  PIG  IRON  BY   ANALYSES. 

Previous  to  1890  almost  all  pig  iron  was  graded  by 
fracture  and  piled  according  to  the  open  character  of 
the  grain,  the  most  open  iron  being  used  for  the  softest 
castings  and  the  close  grained  for  the  hard  ones,  as 
shown  in  the  last  chapter.  Furnacemen  and  founders 
gradually  came  to  learn,  by  means  of  following  chem- 
ical analysis,  that  such  was  not  reliable  and  could  often 
be  deceptive.  This  has  been  so  thoroughly  demon- 
strated that  it  is  now  (1901)  rare  to  find  a  furnaceman 
paying  any  attention  to  the  appearances  of  fracture, 
unless  a  customer  asks  him  to,  and  instead  being 
wholly  guided  by  a  knowledge  of  the  chemical  constit- 
uents of  the  iron.  While  this  is  now  the  current  prac- 
tice of  most  all  furnacemen  and  about  75  per  cent,  of 
foundrymen,  we  have  the  evil  of  disabusing  the  general 
sense  of  numbering  the  grades  which  certain  analyses 
will  give.  For  example,  a  No.  i  iron  is  generally 
supposed  to  be  such  as  will  give  soft  castings  in  those 
ranging  from  one  inch  in  thickness  down  to  stove  plate. 
Nevertheless,  we  have  today  (1901)  furnacemen  desig- 
nating pig  iron  as  No.  i  that  would  run  white  in  stove 
plate  and  require  castings  to  be  a  foot  thick  or  more  in 
order  to  be  sufficiently  soft  to  be  drilled,  etc.  An  iron 
to  be  No.  i  by  analysis  should  contain  at  least  from 


GRADING    PIG    IRON    BY    ANALYSES.  149 

2.75  to  3.00  per  cent,  of  silicon  and  sulphur  from  .01  to 
.04,  with  manganese  below  i.oo  and  phosphorus  ranging 
from  .30  to  i.oo.  Evidence  of  evils  to  come  from  the 
above  practice  of  irregularity  in  grading  pig  iron  by 
analysis  can  be  found  in  Mr.  Seymour  R.  Church's 
first  edition  of  "  Analysis  of  Pig  Iron."  In  this  work 
we  find  pig  irons  called  No.  i  by  their  makers 
ranging  in  silicon  from  one-half  of  one  per  cent.  (.50) 
to  four  per  cent.  (4.00).  Furthermore,  the  wildest 
kind  of  confusion  exists  as  to  numbers  and  trade- 
marks, etc.,  supposed  to  designate  the  special  qualities 
of  the  different  grades  of  pig  iron  reported. 

To  correct  this  evil  and  to  establish  uniform  methods 
for  grading,  the  author  presented  a  paper  on  the  sub- 
ject to  the  Pittsburg  Foundrymen's  Association, 
March,  1901.  This  paper  embodied  the  table  seen  on 
page  152  and  some  of  the  arguments  presented  in  this 
chapter.  The  Pittsburg  Foundrymen's  Association 
was  so  impressed  with  the  importance  of  this  work 
that  a  committee  was  appointed,  with  the  author  as 
chairman,  to  advance  the  work  and  carry  it  to  the 
American  Foundrymen's  Association  Convention  at 
Buffalo,  N.  Y.,  June,  1901.  To  this  end,  circulars 
were  issued  regarding  the  work  and  replies  requested 
as  to  opinion  of  the  methods  presented  or  suggestions 
for  others.  Fully  two-thirds  of  the  many  replies 
received  endorsed  the  author's  method,  shown  in  this 
chapter,  and  which  differs  only  (Table  22)  in  permitting 
higher  sulphurs  in  grades  Nos.  i  to  3,  whereas  the 
original  plan  restricted  it  not  to  exceed  .02  for  No.  i 
and  .03  for  Nos.  2  and  3.  However,  it  should  be  born 
in  mind  that  if  sulphur  reaches  .04  the  silicon  might 
often  be  required  at  the  highest  point  of  any  one 


150  METALLURGY    OF    CAST    IRON. 

grade,  as,  for  example,  an  iron  with  2.75  per  cent,  of 
silicon  and  but  .01  of  sulphur  would  give  nearly  as 
soft  a  casting  as  one  that  might  contain  3.00  silicon 
with  .04  sulphur,  and  which  is  a  system  upon  which 
all  the  various  grades  seen  in  Table  22,  page  152,  are 
divided. 

Great  interest  was  manifested  in  the  subject  of  this 
chapter  at  the  American  Foundrymen's  Association 
Convention  in  1901  and  several  plans,  aside  from  the 
author's,  were  presented.  A  committee  was  appointed, 
with  the  author  as  chairman,  to  continue  the  work  and 
report  progress  at  the  convention  to  be  held  in  1902. 
It  is  with  a  view  of  assisting  this  work  as  much  as 
possible  that  the  author  presents  this  chapter,  and  he 
would  like  to  publish  all  the  methods  presented  at 
the  convention  did  space  permit.  However,  any  one 
desiring  to  read  what  others  presented  to  the  con- 
vention on  the  subject  can  do  so  by  procuring 
copies  of  the  American  Foundrymen's  Association 
Journal  for  July,  or  the  Iron  Trade  Review  of  June 
13,  1901. 

The  author's  extended  experience,  obtained  by  closely 
following  variations  in  the  hardness  of  castings  or  test 
bars  due  to  changes  in  silicon  and  sulphur,  with  the 
other  elements  fairly  constant,  is  such  that  he  can  safely 
say  that  where  sulphur  is  kept  constant  every  increase 
of  .25  per  cent,  silicon  should  change  the  grade  of  pig 
iron  one  number  in  all  iron  ranging  to  3.00  or  4.00  per 
cent,  in  silicon.  It  takes  less  sulphur  than  any  other 
element  to  effect  a  change  in  the  grade  or  hardness  of 
a  casting.  A  change  of  one  point  of  sulphur  (.01)  can 
often  neutralize  the  effect  of  eight  to  fifteen  points 
of  silicon.  This  will  be  better  understood  by  referring 


GRADING    PIG    IRON    BY    ANALYSES.  151 

to  Table  21  which  shows,  approximately,  the  increase 
in  silicon  and  sulphur  necessary  to  maintain  a  uniform 
hardness  (or  a  fairly  constant  condition  of  the  carbons) 
in  re-melted  pig  iron  that  will  not  vary  thirty  points  in 
manganese  and  fifteen  points  in  phosphorus,  a  range 
that  is  within  the  limits  of  what  generally  exists  in 
irons  made  from  similar  ores,  fuels,  and  fluxes.  In 
brief,  Table  21  shows  that  if  an  iron  containing  2.00 
per  cent,  silicon  should  have  its  sulphur  increased  from 
.01  to  .06,  then  in  order  to  maintain  an  approximately 
equal  hardness  in  similar  test  bars  or  castings  the  sili- 
con would  have  to  be  increased  fifty  (.50)  points.  In 
coke  irons,  as  a  rule,  the  lower  the  silicon  the  higher 

TABLE    21. 


Sulphur  

.01 

.02 

•03 

.04 

•°5 

.06 

Silicon 

2.OO 

2.10 

2.20 

2.30 

2.40 

2:50 

the  sulphur  will  be  found.  In  establishing  standards 
the  amount  of  sulphur,  therefore,  should  be  considered 
as  well  as  the  silicon.  Recognizing  this  fact  in  con- 
nection with  the  statement  above,  which  makes  a 
distinction  in  grade  at  every  .25  per  cent,  of  silicon. 
Table  22  is  presented  by  the  author  as  a  method  for 
numbering  grades,  which,  if  adopted,  would  greatly 
lessen  the  confusion  and  trouble  we  find  the  practice 
created  previous  to  1901. 

By  the  method  seen  in  Table  22,  page  152,  one  can 
form  some  fair  idea  of  the  hardness  to  be  expected  in 
castings  from  pig  iron,  when  ordering  by  number  in 
different  grades  of  iron.  Then  again,  if  adopted,  it 
would  give  a  fair  knowledge  of  the  value  of  an  iron 
from  a  reading  of  the  market  reports  of  prices,  by 


METALLURGY    OF    CAST    IRON. 


numbers,  for  as  a  rule  the  more  silicon  in  iron  the 
greater  its  value  in  any  special  brand.  Even  if  the 
trade  should  not,  in  time  to  come,  require  a  number- 
ing of  grades  on  account  of  the  practicability  of  order- 
ing by  specified  analysis  in  purchasing  foundry, 
bessemer,  gray  forge,  mill,  or  basic  pig  irons,  it  will 
be  essential  to  have  some  means  of  brevity  as  by  num- 
bers in  denoting  grades  in  the  market  reports  of 
prices :  And  the  method  presented  by  the  author  in 
Table  22  seems  to  him  as  simple  and  practical  as 
could  be  offered  or  enforced  by  practice  for  such 
ends. 

TABLE    22. 


Silicon.          .         

No.  i  Iron. 
2.75  to  3.00 

No.  2. 

2.50  to  2.75 

No.  3. 

2.25  tO  2  50 

No.  4. 

2.OO  tO  2  25 

Sulphur  ,  

.01  to    io4 

.01  to    .04 

.01  to    .04 

.01  to    .04 

Silicon. 

No.  5. 

1.75  to  2.  TO 

No.  6. 
1.50  to  1.75    ' 

No.  7. 
1.25  to  i  50 

No.  8. 
i.oo  to  i  25 

Sulphur  

.02  tO     .05 

.02  tO     .05 

.03  to    .06 

.03  to    .06 

Silicon 

No.  9. 

75  to  i  oo 

No.  10. 
50  to    .75 

Sulphur  

.04  to    .07 

.04  to    .10 

Numbering  the  grades  from  i  to  10,  advancing  in 
silicon  .25  and  sulphur  .01  to  .04  or  more  in  each  grade, 
as  shown  in  Table  22,  gives  a  range  that  may  be  said 
to  include  all  the  necessary  irons  that  are  now  used  in 
making  castings,  or  for  the  manufacture  of  'steel  or 
wrought  iron,  except  the  so-called  softeners  or  ferro- 
silicon  irons.  When  purchasing  ferro -silicons  or  soft- 
eners one  should  also  know,  aside  from  the  silicon,  the 
amount  of  sulphur,  phosphorus,  manganese,  and  total 
carbon  they  contain,  as  these  elements  can  vary  greatly 
in  the  same  brand,  or  similar  percentages  of  high 
silicon  iron,  vary  much  more  than  in  irons  having  less 


y^Tl  B  R  A  ft  y 

ff  OF  THE 

I  UNIVER6IT 

GRADING    PIG    IRON    BY    ANALYSES.      ^L  I53F 

than  the  3.00  per  cent,  of  silicon  shown  in  Table  22. 

It  is  not  to  be  understood  by  the  above  that  no  atten- 
tion is  to  be  paid  to  the  manganese,  phosphorus,  or 
total  carbon  when  ordering  iron  by  numbers,  as  in 
Table  22.  In  some  cases  such  will  be  very  necessary, 
as  one  founder  may  require  very  high  or  low  manga- 
nese, phosphorus,  or  total  carbon,  while  another  may 
stand  a  wide  variation  in  these  elements  as  long  as  the 
silicon  and  sulphur  are  best  suited  for  the  work.  To 
designate  the  manganese,  phosphorus,  or  total  carbon 
in  any  system  of  grading  by  analysis  in  numbers,  that 
is  intended  for  universal  use,  could  meet  with  little 
favor  for  the  reason  that  furnacemen  cannot  vary 
these  in  unison  with  variations  of  silicon  and  sulphur 
in  obtaining  different  grades. 

The  manganese,  phosphorus,  and  total  carbon,  the 
author  believes,  will  be  found  to  be  best  omitted  from 
any  universal  system  of  numbering  grades.  When  a 
founder  desires  any  special  percentages  in  one  or  all  of 
these  three  elements  in  purchasing  foundry,  bessemer, 
gray  forge,  mill,  or  basic  irons,  he  can  designate  just 
what  he  would  like,  aside  from  stating  the  number  of 
the  grade  desired,  and  if  he  cannot  get  what  he  desires 
at  one  furnace  he  will  have  to  try  others.  The  man- 
ganese phosphorus,  and  total  carbon  will  not,  as  a  rule 
(as  shown  in  Chapter  XVII.),  vary  to  any  injurious 
extent  for  the  general  run  of  ordinary  castings,  in  any 
one  brand  of  iron  made  from  like  ores,  fuels,  and 
fluxes,  in  irons  having  less  than  4.00  of  silicon,  as  the 
silicon  and  sulphur  can ;  and  hence  the  reason  why  the 
author  suggests  confining  grading  by  analysis  in  num- 
bers to  the  silicon  and  sulphur,  as  seen  in  Table  22. 
The  class  of  castings  in  which  it  is  generally  most 


154  METALLURGY    OF    CAST    IRON. 

desirable  to  know  the  manganese,  phosphorus,  and 
total  carbon  contents  are  such  as  stove  plate,  light 
work,  and  the  general  run  of  chilled  castings.  From 
the  above  it  can  be  seen  that  it  would  generally  be 
advisable  for  furnacemen  in  advertising  their  irons  to 
state,  together  with  the  numbers  of  the  grades  or 
brands  they  make,  what  percentage  or  range  of  man- 
ganese, phosphorus,  and  total  carbon  their  irons  gener- 
ally contain,  as  there  are  conditions  demanding  varying 
percentages  of  these  elements  met  with  that  would  the 
greater  enhance  the  sale  of  the  irons  were  these  points 
made  known.  As,  for  example,  a  founder  making 
very  thin  castings  would  require  higher  phosphorus, 
which  gives  more  fluidity  to  iron  than  is  available  in 
some  regular  No.  i  grades.  Then  again,  it  is  often 
necessary  to  know  what  manganese  an  iron  contains, 
as  when  it  is  more  than  .50  its  influence  is  to  harden. 
With  regard  to  the  carbon,  the  ' '  total ' '  is  all  that  is 
generally  required.  Giving  the  percentage  of  what  is 
combined  or  free  carbon  in  pig  iron  generally  tells 
nothing  further  than  the  melting  qualities  of  the 
metal.  In  this,  the  more  the  carbon  is  combined  the 
easier  or  quicker  the  iron  melts  —  a  fact  discovered  by 
the  writer  several  years  ago,  and  confirmed  by  Dr.  R. 
Moldenke  by  further  experiment.  If  a  knowledge  of 
the  combined  or  graphitic  carbon  contents  of  pig  iron 
was  of  any  real  value  in  grading  pig  iron  by  analysis, 
grading  could  be  done  effectually  by  fracture  or  hard- 
ness, and  the  only  determination  required  would  be 
that  of  the  total  carbon,  phosphorus,  or  manganese, 
according  as  information  might  be  desired  of  one  or 
all  of  these  ingredients.  It  is  not  the  author's  idea,  that 
because  the  grades  are  divided  at  every  quarter  of  one 


GRADING    PIG    IRON    BY    ANALYSES.  155 

per  cent,  in  silicon  and  the  sulphur  ranging  from  .01 
to  .10  per  cent.,  as  shown  by  Table  22,  that  any 
furnaceman  should  be  compelled  to  fill  orders  from 
any  one  particular  grade  or  number  of  iron.  It  is 
intended  that  the  number  ordered  should  indicate  the 
grade  of  iron  the  consumer  desired,  and  to  fill  the  order 
the  furnaceman  could  ship  any  number  of  grades  from 
which  an  average  might  be  obtained  which  corresponds 
to  the  grade  order.  If,  for  example,  in  following  the 
method  of  grading  advanced  in  Table  22  one  should 
desire  a  No.  4  iron,  he  can  accept  irons  ranging  from 
No.  i  to  No.  8  to  make  an  average  which  would  give 
the  grade  No.  4  desired,  provided  he  knew  the  grade 
of  every  car  delivered  at  his  yard.  There  is  surely 
sufficient  margin  in  this  method  to  permit  the  furnace- 
man to  fill  an  order  for  any  particular  grade  of  iron 
for  the  great  majority  of  purchasers. 

When  foundry  men,  as  a  rule,  desire  to  produce  cast- 
ings that  are  to  be  of  some  particular  softness  or  hard- 
ness, and  we  know  that  a  change  of  twenty-five  points 
in  silicon  and  two  points  in  sulphur  can  cause  them  to 
vary  from  the  best  grade  which  should  exist  in  their 
castings,  the  author  fails  to  perceive  the  impracticabil- 
ity of  any  furnaceman  accepting  orders  for  foundry, 
bessemer,  gray  forge,  mill,  or  basic  pig  irons  by  the 
method  of  numbering  the  grades  from  i  to  10,  which 
he  has  advanced  in  Table  22.  In  fact,  any  greater 
margin  would  fail  to  denote  the  true  character  of  the 
iron  desired  and  could  cause  such  misunderstanding 
as  to  result  seriously  for  both  furnaceman  and  founder. 
What  is  required  is  a  method  of  numbering  that  will 
denote  when  the  character  of  iron  is  noticeably 
changed,  and  not  something  that  is  so  flexible  that  any 


156  METALLURGY   OF    CAST    IRON. 

change  from  one  number  to  another  would  make  a 
mixture  which  would  vary  so  greatly  as  to  make  cast- 
ings so  unfit  for  their  use  that  they  would  be  con- 
demned ;  and  this  some  of  the  methods  that  have  been 
advanced  would  do. 

One  objection  made  to  the  author's  method  of  grad- 
ing, seen  in  Table  22,  is  that  errors  in  analysis  could 
make  a  difference  of  .25  per  cent,  silicon  and  .01  in 
sulphur.  Granting  this  to  be  true,  as  has  often  been 
the  case,  does  this  offer  any  just  cause  for  the  con- 
sumer not  defining  as  closely  as  he  may  the  grade  he 
desires  to  correspond  with  any  range  in  numbers  from 
one  to  ten  in  Table  22?  If  such  difference  in  analysis 
continued  to  exist  they  could  injure  the  consumer  as 
much  as  if  grades  were  divided  by  one  per  cent,  of 
silicon,  instead  of  .25  per  cent,  as  shown.  To  the 
author's  view,  this  is  a  factor  that  should  have  no 
weight  in  deciding  the  division  of  grades.  However, 
by  the  use  of  the  American  Foundrymen's  Association 
standardized  drillings,  and  the  adoption  of  more 
uniform  methods  of  making  analyses  —  which  is  sure 
to  come  and  for  which  work  the  author  is  chairman  of 
a  committee  appointed  by  the  American  Foundrymen's 
Association  in  1901  to  advance  such  improvement  — 
there  will  be  little  excuse  for  any  great  difference  in 
the  chemical  analysis  of  one  sample  of  drillings  by 
different  chemists.  There  is  much  more  that  might 
be  said  on  the  subject  of  this  chapter,  but  the  author 
trusts  that  the  principles  herein  advanced  will  aid  the 
work  of  bringing  about  the  reform  in  grading  or  buy- 
ing pig  iron  by  analysis  which  this  chapter  advocates, 
and  which  almost  all  now  concede  should  be  accom- 
plished. 


CHAPTER  XXII. 

BESSEMER  vs.  FOUNDRY  IRON. 

That  "  Bessemer  iron  "  can  often  take  the  place  of 
*  'Foundry, ' '  and  in  some  cases  prove  a  better  product 
to  make  castings  with,  is  a  fact  which  few  founders  have 
up  to  this  writing  discovered.  In  the  years  1893  and  1894 
of  business  depression,  Bessemer  pig  was  selling  cheap- 
er than  Foundry  pig.  A  few  founders,  who  did  not  re- 
quire high  phosphorus  and  knew  it,  took  advantage  of 
the  low  price  of  Bessemer.  Founders  never  having 
had  an  experience  with  Bessemer  pig  metal  will  be 
somewhat  surprised  to  learn  that  the  best  experts  can- 
not tell  ' '  Bessemer  ' '  from  * '  Foundry  ' '  by  judging 
of  its  fracture ;  nevertheless  this  is  true.  It  is  only  by 
analysis  that  the  difference  is  to  be  made  known,  and 
that  mainly  exists  in  the  phosphorus  being  lower  in 
Bessemer  than  Foundry,  as  illustrated  in  Table  30, 
page  215. 

Regular  Bessemer  ranging  from  1.40  to  1.60  in  sili- 
con, .010  to  .030  in  sulphur  and  about  .45  in  manganese, 
can  often  be  well  used  for  hydraulic  or  steam  cylin- 
ders, heavy  dies,  machinery  castings,  and  for  gear 
wheels  of  one  and  one-half  inch  pitch  and  upwards. 

For  ordinary  machinery  castings  that  average  from 
one  and  one-half  inches  up  to  two  inches  thickness  of 
metal,  Bessemer  ranging  from  1.60  to  1.90  in  silicon 
would  be  found  to  work  very  well.  The  author  has. 


158  METALLURGY    OF    CAST    IRON. 

used  Bessemer  1.85  to  2.00  in  silicon  with  excellent 
success  in  making  electric  street  car  motor  gear 
wheels.  These  wheels,  as  many  know,  are  cast  in  a 
4 'blank  "and  the  teeth  are  milled  out.  When  first 
starting  in  to  make  these  castings  it  was  a  *  *  trick  ' '  of 
ours  to  take  a  pin  hammer  and  strike  upon  the  teeth 
of  a  spoiled  wheel  until  the  tooth  would  flatten  out  as 
if  one  were  pounding  a  piece  of  wrought  iron.  This 
was  partly  due  to  low  phosphorus,  causing  the  iron 
to  possess  a  malleable  toughness.  Bessemer  con- 
taining from  1.95  to  2.25  silicon  would  make  an  excel- 
lent iron  for  all  castings  such  as  ordinary  weight  of 
lathes  and  planers.  For  heavy  punches  and  shears  it 
would  be  well  to  have  the  iron  range  from  1. 10  to  1.30 
in  silicon,  with  sulphur  about  .030  in  the  pig.  It  is  to 
be  remembered  that  owing  to  Bessemer  being  low  in 
phosphorus  it  is  not  as  fluid  and  does  not  run  a 
mould  as  well  as  Foundry  iron.  Nevertheless,  it  can  be 
melted  * '  hot ' '  enough  to  run  castings  as  thin  as 
* '  stove  plate, ' '  if  the  liquid  metal  is  not  retained  too 
long  in  the  ladle  or  has  not  to  run  up  too  far  in  a  mould, 
or  a  long  distance  from  the  ' '  gate ;  ' '  but  cannot  be 
recommended  for  such  light  work. 

A  founder  can  utilize  common  scrap  with  Bessemer 
pig  metal  for  all  work  above  stove  plate  thickness,  as 
in  this  respect  sufficient  silicon  can  be  obtained  in 
"  Bessemer, ' '  as  well  as  in  "  Foundry, ' '  to  soften  scrap, 
and  thus  often  assist  in  cheapening  a  mixture.  Sili- 
con does  not,  as  a  general  thing,  go  as  high  in  Bes- 
semer as  in  Foundry.  When  silicon  exceeds  2.50  per 
cent,  in  Bessemer,  it  is  generally  called  an  "off  Bes- 
semer," the  same  as  when  it  exceeds  .  10  in  phosphorus. 
To  be  over  2.50,  the  limit  for  silicon  in  regular  Bes- 


BESSEMER    VS.    FOUNDRY    IRON.  159 

semer,  is  not  so  objectionable  to  steel  men  as  it  is  for 
the  phosphorus  to  be  over  .  10.  Steel  works  will  often 
accept  Bessemer  over'  2.50  in  silicon,  but  seldom  ac- 
cept phosphorus  over  .10,  unless  the  iron  is  used  to 
make  steel  by  the  "  basic  process,"  a  method  by  which 
phosphorus  can  be  greatly  eliminated  from  the  iron  by 
reason  of  qualities  in  the  lining1  having  an  affinity  for 
phosphorus.  Bessemer  iron,  to  be  such,  in  the  regular 
sense,  must  not  have  over  one-tenth  of  one  per  cent, 
of  phosphorus,  which  is  a  small  quantity  compared 
with  one  per  cent,  often  utilized  in  Foundry  iron  in 
order  to  give  the  molten  metal  good  life  and  fluidity. 

It  is  to  be  understood  that  in  all  the  mixtures  shown 
on  pages  157  and  158  the  sulphur  is  not  to  exceed  .030 
or  the  manganese  .50  in  the  pig;  if  it  does,  then  higher 
silicon  will  be  necessary  in  proportion  to  their  increase ; 
also,  that  no  scrap  is  intended  to  be  mixed  with  the 
percentages  of  silicon  given.  Should  it  be  desirable 
to  mix  scrap  with  the  pig,  which,  of  course,  if  not 
Bessemer  scrap,  would  raise  the  phosphorus,  to  take 
the  mixture  out  of  the  category  of  Bessemer  iron,  and 
in  either  case  with  any  kind  of  scrap,  it  would  call  for 
an  increase  of  silicon  in  the  pig  metal,  so  as  to  prevent 
the  mixture  from  producing  too  hard  a  "grade,"  as 
defined  in  the  last  paragraph,  page  158.  For  further 
notes  on  Bessemer,  see  pages  146  and  215. 


CHAPTER.  XXIII. 

CHARCOAL   vs.   COKE  AND    ANTHRACITE 

IRON. 

The   past  advancement   in    utilizing  chemistry  in 

making  mixtures  of  cast  iron  has,  among  other 
changes  in  founding,  resulted  in  causing  many  firms 
to  make  castings  of  various  types  from  coke  irons, 
whereas  for  years  past  it  has  been  thought  that  char- 
coal was  the  only  brand  permissible  to  be  used.  It  is 
no  reason  because  malleable  iron  founders  and  some  car 
wheel  and  chill  roll  makers  have  discovered  that  coke 
and  anthracite  iron  can  be  made  to  answer  their  pur- 
pose that  charcoal  iron  is  sure  to  pass  into  oblivion. 
A  peculiarity  between  "  Bessemer  "  and  "  Foundry" 
iron  lies  in  the  fact  that  one  cannot  be  told  from  the 
other  in  yards,  single  pigs  or  piles,  in  judging  them 
by  fracture.  This  cannot  be  held  to  be  true  of  char- 
coal vs.  coke  iron.  If  there  were  two  yards  of  pig 
metal,  one  being  charcoal  and  the  other  being  all  coke 
or  anthracite  iron,  any  one  at  all  familiar  with  such 
irons  can  generall)T  tell  the  class  of  iron  each  yard  con- 
tains. We  may  occasionally  see  single  pieces  or  piles 
of  coke  or  anthracite  pig  iron  which  will  resemble 
charcoal  so  closely  as  to  make  it  difficult  to  decide  its 
true  brand,  but,  in  a  general  way,  charcoal  iron  is 
distinguishable  from  coke  or  anthracite  iron. 


CHARCOAL,   VS.   COKE    AND    ANTHRACITE    IRQN.         l6l 

The  greater  the  temperature  in  a  blast  furnace,  the 
more  silicon  can  iron  absorb.  The  lower  heat  derived 
from  charcoal  furnaces  causes  less  silicon  to  be  taken 
up  than  by  iron  in  coke  or  anthracite  furnaces.  From 
this  circumstance,  combined  with  the  fact  that  charcoal 
fuel  is  free  from  sulphur,  we  find  that  charcoal  iron 
generally  contains  very  little  sulphur,  with  low  silicon. 
The  more  general  uniform  workings  of  charcoal  over 
coke  furnaces  and  absence  of  sulphur  in  charcoal  iron, 
leaves  much  less  chance  for  the  other  elements  — 
silicon,  manganese,  phosphorus,  etc.,  to  cause  radical 
variation  in  the  size  of  the  grains ;  and  hence  we  find, 
as  a  general  rule,  that  charcoal  iron  is  more  uniform  in 
grain  than  coke  or  anthracite  irons. 

The  greater  strength  and  homogeneity  of  charcoal 
over  the  present  coke  or  anthracite  iron,  also  in  its  pos- 
sessing very  low  sulphur,  as  a  rule,  will,  in  the  author's 
estimation,  forbid  its  expulsion  from  the  market.  There 
are  certain  kinds  of  work  for  which  charcoal  will  gen- 
erally prove  superior  over  other  irons.  These  can  be 
classed  in  the  following  order:  (i)  Chilled  work,  (2) 
gun  manufacture,  (3)  hydraulic  and  steam  cylinder 
castings.  Heavy  gearings  and  large  castings  require 
high  strength,  combined  with  softness  sufficient  to 
permit  finishing.  Coke  iron  is  now  used  in  nearly  all 
the  specialties,  but  where  it  is  intended  to  replace 
charcoal  special  care  is  often  necessary  to  watch  the 
sulphur  contents  in  order  to  get  them  as  low  as  possible. 
Where  the  coke  or  coal  fuel  and  ore  are  very  low  in 
sulphur,  coke  or  anthracite  iron  can  be  made  which 
may  often  answer  many  purposes  of  charcoal  pig. 
Charcoal  pig  iron,  on  the  whole,  is  poorer  in  silicon 
and  phosphorus,  as  well  as  sulphur,  than  a  coke  or 
anthracite  pig  metal.. 


162  METALLURGY    OF    CAST    IRON. 

Charcoal  fuel  contains  no  sulphur,  and  if  the  ore 
and  flux  are  likewise  free  from  it  an  iron  will  be 
obtained  free  of  sulphur  —  something  which  cannot  be 
said  of  coke  or  anthracite  iron.  Let  charcoal  iron  be 
melted  in  an  '  *  air  furnace  ' '  instead  of  a  cupola,  where 
the  iron  must  be  mixed  with  coke  or  coal,  and  it  can 
then  clearly  demonstrate  its  superiority  over  coke  or 
anthracite  iron.  To  melt  charcoal  in  a  cupola  greatly 
impairs  its  superior  qualities  and  brings  it  largely  on 
a  level  with  coke  or  anthracite  iron.  Coke  or  anthra- 
cite will  often  answer  well  for  an  approximation,  but 
to  obtain  the  very  best  mixture  for  chilled  work,  guns, 
etc.,  charcoal  iron  will  ever  remain  the  king  metal  of 
cast  irons,  when  melted  in  an  air  furnace,  unless  mod- 
ern advance  arranges  to  eliminate  sulphur,  etc.,  from 
metal  and  * '  refine  ' '  the  iron  before  it  is  cast  into  pigs 
in  such  a  manner  as  to  be  relied  upon,  or  while  being 
re-melted  in  the  cupola.  For  analyses  of  charcoal  iron, 
see  pages  268,  269  and  299. 

Refining  iron  means  the  lowering  or  removal  of 
some  impurities — carbon,  silicon,  and  manganese  being 
classed  with  them  in  this  instance.  The  process,  of 
course,  increases  the  percentage  of  iron  in  the  product 
but,  for  casting  purposes,  should  not  be  carried  too  far. 
Unfortunately,  sulphur  and  phosphorus  will  not  go  as 
readily  as  manganese  and  silicon,  in  fact,  in  the  ordi- 
nary refining  of  a  bed  they  will  not  go  at  all ;  hence 
the  value  of  refining  is  to  be  looked  for  in  the  removal 
of  the  mechanically  mixed  slag,  the  lowering  of  the 
silicon  and  manganese,  and,  in  some  cases,  the  carbon 
contents,  with  the  consequent  increase  in  the  com- 
bined carbon  of  the  product  and  the  closing  up  of  the 
grain. 


CHAPTER  XXIV. 

THE   DECEPTIVE   APPEARANCE  OF   THE 
FRACTURE   OF  PIG  IRON.* 

Progressive  furnacemen  and  foundrymen  have  ex- 
perienced few  changes  in  their  practice  that  have  been 
more  radical  in  character  or  far-reaching  in  benefit, 
than  those  made  by  the  adoption  of  chemical  analysis 
to  correctly  define  the  grade  of  pig  iron.  The  change 
was  such  a  sensible  one  that  many  are  annoyed  that  in 
this  age  of  science  they  have  not  always  utilized  chem- 
istry in  their  practice.  And  not  until  we  bring  to 
mind  the  old-time  prices  paid  for  castings,  can  we 
realize  why  commercial  success  was  at  all  possible  to 
many  following  the  old  school  methods  of  judging  the 
grade  of  pig  iron.  While  the  benefits  obtained  by 
adopting  chemical  analysis  in  foundry  practice  are 
,  generally  very  great,  the  advance  has  been  slow.  This 
is  on  account  of  the  prejudice,  selfishness,  and  conser- 
vatism that  all  new  departures  in  any  calling  must 
meet  and  set, aside.  The  opposition  that  existed,  and 
is  yet  in  force,  against  the  adoption  of  grading  by 
chemical  analysis  has  caused  the  author  to  ex- 
pend much  time  and  money  in  its  defence.  It  is 
often  interesting  to  investigate  the  reasons  for 
rejecting  the  new-school  practice  that  members 

*  A  revised  edition  of  a  paper  presented  by  the  author  to  the 
Pittsburg  meeting  of  the  American  Foundrymen's  Association, 
May,  1899. 


164  METALLURGY    OF    CAST    IRON. 

of  the  old  set  up  against  its  advocates.*  Not  long 
ago,  as  an  example,  in  discussing  the  merits  of  work- 
ing by  chemical  analysis  with  an  old  experienced 
founder  who  had  never  mixed  his  metals  by  this 
method,  he  expressed  the  belief  that  if  a  cast  of  nice 
open-grained  pig  iron  did  not  give  a  softer  iron  than  a 
close-grained  pig  mixture  it  was  because  of  some  local 
condition  not  being  controlled;  as,  for  example,  he 
claimed  that  the  cupola  might  not  have  been  daubed 
properly,  or  the  bed  not  well  lighted  before  the  iron 
was  charged,  or  the  charge  might  not  have  been  placed 
evenly,  or  that  the  stock  hung  up.  Then  again,  he 
claimed  that  it  might  be  due  to  other  conditions,  such 
as  are  found  in  bad  scrap  iron,  changeable  weather, 
difference  in  fuels,  fluxes,  or  variable  blast  pressures, 
to  cause  fast  or  slow  melting,  etc.  When,  as  practical 
foundrymen,  we  know  that  such  varying  conditions 
may  at  all  times  affect  mixtures  and  cause  a  soft  iron 
to  be  hard,  we  are  forced  to  confess  that  the  old-school 
fellows  may  continue  their  method  for  years,  if  they 
are  in  any  way  prejudiced  against  the  new-school  prac- 
tice, before  events  may  transpire  to  convince  them  that 
by  following  chemical  analysis  they  will  greatly 
decrease  their  mishaps,  for  the  simple  reason  that  if 
an  open  cast  of  pig  metal  does  happen  to  give  them  a 
hard  iron  they  have  nearly  a  dozen  evils  or  excuses  to 
which  they  can  charge  their  poor  results. 

There  are  several  ways  in  which  self-interest  can 
retard  the  progress  of  chemical  analysis  in  founding. 
As  an  example  we  will  cite  two  cases.  The  first  lies 
in  the  power  of  furnacemen  knowing  the  utility  of 
chemical  analysis,  and  lack  of  that  knowledge  by  the 

*  For  the  latest  in  support  of  old-school  fallacies  and  retarding 
the  advance  of  the  new,  see  page  179. 


APPEARANCE    OF    THE    FRACTURE    OF    PIG    IRON.        165 

old-school  fotmdrymen.  To  illustrate  how  the  latter 
may  be  duped  by  making  them  think  their  practice 
correct:  A  well-known  firm,  standing  high  in  its 
ability  to  cast  heavy  machinery,  recently  sent  an  order 
to  a  furnaceman  for  one  car  of  strictly  all  open -grade 
iron,  to  make  strong  castings  for  a  special  job.  The 
author  was  consulted  as  to  the  analysis  necessary,  as 
the  furnaceman  knew  he  could  select  the  open  iron  in 
almost  any  grade  of  silicon.  Upon  learning  the  char- 
acter of  the  castings  required  from  the  furnaceman,  the 
author  recommended  silicon  between  i.oo  and  1.25, 
with  sulphur  about  .030.  A  car  of  as  beautiful  open  - 
grained  coke  iron  as  was  ever  seen  was  sent  to  the 
founder.  Its  results  pleased  him  so  much  that  in  a 
few  weeks  the  second  order,  * '  Send  me  another  car  of 
strictly  open -grade  iron,  same  as  last,"  came  in.  The 
furnaceman,  knowing  the  utility  of  chemical  analysis, 
referred  to  his  books  and  duplicated  his  last  analysis, 
being  careful,  of  course,  to  load  nothing  but  an  all 
open-grained  iron,  as,  if  he  had  sent  a  close-grained 
iron  it  would  have  been  condemned.  Now,  this  fur- 
naceman is  not  going  out  of  his  way  to  advocate  the 
utility  of  chemical  analysis  to  that  foundryman,  and  it 
would  be  almost  useless  for  anyone  else  to  attempt  to 
do  so,  as  the  founder  is  stubborn  in  the  belief  that  it 
is  the  open -grained  iron  of  that  peculiar  brand  which 
was  wholly  responsible  for  obtaining  the  results  he 
desired.  Then  again,  should  this  founder,  on  account 
of  a  difference  in  price,  change  to  another  furnaceman 
who  was  not  thoroughly  posted  in  making  mixtures 
for  different  castings,  and  who  might  not  have  had  the 
forethought  to  consult  some  expert  of  the  new  school 
in  regard  to  analysis,  the  chances  are  that  his  open- 


1 66  METALLURGY    OF    CAST    IRON. 

grained  iron  would  have  given  him  too  weak  a  result 
in  his  castings,  on  account  of  there  being  chances  of 
its  being  too  high  in  silicon;  or  again,  by  ignoring 
analysis  and  taking  open  iron  wherever  found,  he 
might  receive  some  so  low  in  silicon  as  to  make  his 
casting  white  iron.  The  author  has  heard  shippers 
say,  * '  Well,  if  the  fool  does  not  know  better  than  to 
order  iron  by  fracture,  let  him  suffer  his  losses. ' ' 
The  author  has  known  cars  of  nice  open  iron  to  have 
but  .75  up  to  1.25  in  silicon  go  to  founders  wishing 
soft  light  castings,  simply  because  they  insisted  that 
the  iron  be  opened-grained  and  ignored  analysis. 
Such  iron  could  do  nothing  other  than  give  hard 
iron  in  any  castings  less  than  2  inches  thick.  But  as 
long  as  this  founder  had  his  open-grained  iron  he 
could  turn  to  changes  in  the  fuel,  scrap  irons,  blast, 
weather,  methods  of  charging,  etc.,  to  make  excuses  for 
his  ill  results,  and  not  until  such  a  paper  as  this,  ex- 
posing the  true  cause  of  his  trouble,  might  by  chance 
fall  into  his  hands  is  there  any  hope  of  his  being  made 
a  follower  of  the  new-school  practice. 

The  second  illustration  of  where  self-interest  has 
retarded  the  advance  of  chemical  analysis  lies  in 
advocating  the  use  of  testing  machines,  as  affording 
the  founder  sufficient  means  to  regulate  his  mixtures 
without  resorting  to  chemical  analysis.  Testing  ma- 
chines have  their  place,  and  most  founders  should 
possess  one,  but  the  practice  of  taking  advantage  of 
the  prejudice,  etc.,  of  the  old-school  methods  to  antag- 
onize the  advance  and  true  utility  of  chemical  analysis 
in  the  self-interest  of  a  more  rapid  sale  of  testing 
machines,  is  to  be  deplored. 

The  foundation  of  the  old-school  method  in  regulat- 


APPEARANCE    OF    THE    FRACTURE    OF    PIG    IRON.        167 

ing  mixtures  is  based  on  the  belief  that  the  appearance 
of  pig  fractures,  or  their  hardness,  truly  defines  the 
character  of  iron  as  to  the  degree  of  hardness  it  will 
give  in  castings.  The  founder's  own  experience  in 
knowing  that  he  can  make  soft  and  hard  castings  from 
the  same  ladle,  and  at  one  pouring,  if  he  choose  to  so 


A 


23YJ6  7   8   9   10 


Fi^.37 


construct  his  molds  as  to  make  a  difference  in  the  cast- 
ing rate  of  cooling,  should  be  sufficient  to  prove  to  him 
why  it  is  possible  for  two  furnace  casts  of  pig  metal 
that  are  alike  in  chemical  analysis,  or  will  give  the 
same  results  when  melted,  to  differ  so  widely  in 
appearance  that  a  fracture  from  one  furnace  cast 
will  seem  close-grained  or  hard  in  the  pig,  while  the 
other  will  be  the  reverse.  A  founder  can  take  the  same 
ladle  of  iron,  and  by  pouring  part  of  the  metal 
into  a  sand  mold  and  part  into  one  that  will 


i68 


METALLURGY    OF    CAST    IRON. 


chill  or  solidify  it  quickly,  produce  a  fracture  that 
will  be  close-grained  in  the  one  case  and  open  in  the 
other.  This  is  just  what  the  furnaceman  does  in 
making  sand  cast  pig  iron.  One  part  of  his  tap,  or 
cast  of  iron,  may  run  so  slowly  from  his  furnace  as  to 
* '  chill  the  metal, "  as  it  is  called,  before  it  reaches  the 


H 


I  2  J  4  5  6  7   8   3 

Fig.  51 


10  11 


pig  beds,  while  another  tap  or  cast  may  come  so  fast 
as  to  fill  the  pig  beds  so  rapidly,  or  make  the  pigs 
larger,  that  it  will  take  much  longer  for  the  metal 
to  solidify,  and  thus  make  the  pigs  more  open 
grained  than  ' '  casts  ' '  poured  slower,  or  pouring  smaller 
pigs.  Again,  one  tap  or  cast  at  a  furnace  may  give 
much  hotter  iron  than  another,  and  it  is  natural  that 
the  dull  iron  should  cool  faster  than  the  hot,  and,  if 
both  run  at  the  same  speed  from  the  furnace  down  the 
long  runners  to  the  pig  beds,  the  duller  metal  will 


APPEARANCE    OF    THE    FRACTURE    OF    PIG    IRON.        169 

give  the  closer  grained  iron.  All  should  perceive 
from  this  why  the  same  kind  of  iron  may  have  in  one 
cast  a  close  grain,  and  in  another  an  open  grain. 
As  there  are  but  few  molders  or  founders  who  have 
ever  had  the  opportunity  of  witnessing  a  furnace  cast, 
this  explanation  of  its  workings,  combined  with  their 
own  foundry  experience,  should  assist  many  to  realize 
why  the  fracture  or  hardness  of  pig  metal  is  an  unre- 
liable guide  to  the  iron's  true  grade. 

As  there  are  those  who  are  still  sure  to  contend  that 
open  pig  fractures  mean  a  soft  iron  and  a  close-grained 
iron  a  hard  one,  and  if  different  results  are  obtained  in 
castings  to  charge  such  to  changes  in  fuel,  scrap  iron, 
fluxes,  blast,  weather,  etc.,  the  author  has  selected 
samples  of  pig  iron  shown  in  Figs.  37,  38,  and  39, 
coming  from  two  different  casts,  that  are  a  fair  repre- 
sentation of  the  whole  cast  or  car  of  iron.  If  any  of 
the  old-school  founders  were  asked  to  select  from  these 
a  cast  or  car  of  iron  to  give  soft  castings,  they  would 
pick  out  iron  such  as  sample  A,  seen  in  Figs.  37  and 
39,  while  if  they  desire  to  make  strong  or  hard  castings 
they  would  select  such  irons  as  are  represented  by 
sample  B,  seen  in  Figs.  38  and  39.  In  fact,  if  they 
were  asked  to  use  such  a  cast  or  car  of  iron  as  that 
represented  by  B,  they  would  claim  that  on  account 
of  its  close  grain  and  the  blow-holes  seen  at  D,  the  iron 
was  hardly  fit  for  sash-weights,  let  alone  to  think  it  of 
any  value  to  make  soft  castings. 

In  order  to  convince  the  skeptical,  or  those  not  con- 
versant with  chemical  analysis,  or  the  effect  of  one 
metalloid  upon  another,  that  they  are  in  error,  the 
writer  melted  down  about  one  hundred  pounds  of  each 
of  the  grades  A  and  B  in  his  twin-shaft  cupola,  seen 


170 


METALLURGY    OF    CAST    IRON. 


on  page  241.  In  melting  these  irons  A  and  B  to  make 
the  castings  seen  in  Figs.  37  and  38,  which  range  from 
one-eighth  to  two  inches  in  thickness,  all  conditions 
were  alike  as  near  as  it  was  possible  to  have  them,  so 
that  if  the  open-grained  iron,  A,  gave  a  hard  casting, 


changes  in  fuel,  scrap,  blast,  weather,  etc. —  the  old 
excuse  —  could  not  be  offered  as  an  explanation  to 
befog  the  true  cause  A  sample  of  the  pig  used  and 
sections  of  the  castings  made  from  them  the  author 
displayed  at  the  meeting  at  which  this  paper  was  read 
so  that  all  might  see  them,  and  all  were  invited  to  take 
drillings  from  the  specimens  and  report  whether  their 
analyses  agreed  with  those  presented  in  Table  23,  in 
which  the  letter  A  represents  the  analysis  obtained 


APPEARANCE    OF    THE    FRACTURE    OF    PIG    IRON.        171 

from  the  pig  and  the  castings  seen  in  Fig.  37,  while  B 
gives  that  secured  from  Fig.  38. 


TABLE    23. 


Samples. 

Silicon. 

Sulphur. 

fPig  

1.25 

•°35 

[  Castings 

1.15 

.070 

„ 

fPig  

2.86 

.040 

[  Castings 

2.67 

.060 

The  fracture  seen  in  Fig.  39  being  enlarged  will 
afford  a  better  study  of  the  difference  existing  between 
the  grain  of  the  pig,  samples  A  and  B.  To  the  new- 
school  founder  Table  23  is  sufficient  to  define  the 
results,  or  whether  samples  A  and  B  would  give  the 
soft  or  hard  iron  upon  being  re-melted ;  but  for  the 
old-school  of  founders  Tables  24  and  25  will  best  serve 
such  ends.  A  study  of  these  latter  tables  will  show 
them  that  the  pig  B  which  would  have  been  condemned 
by  those  wishing  to  make  soft  castings,  gave  by  far 
the  least  contraction  and  chill,  so  much  so  that  the  test 
pieces,  only  one-eighth  inch  thick,  as-  seen  at  H,  Fig. 
38,  are  so  soft  as  to  be  readily  drilled,  while  at  K,  Fig. 
37,  made  from  sample  A,  a  drill  was  broken  in  trying 
to  get  a  hole  through  the  thin  piece  one-eighth  inch 
thick.  In  fact,  we  were  foolish  to  try  to  touch  it  with 
a  drill,  as  the  metal  was  nearly  all  chilled  or  white  in 
color.  It  is  also  to  be  said  that  all  the  other  test  pieces 
ranging  from  Nos.  2  to  12  that  were  made  from  the 
pig,  sample  A,  were  also  much  harder  than  those  made 
from  sample  B.  In  measuring  the  depth  of  the  chill, 
pieces  were  broken  off  one  end  of  the  test  bars  as 
seen  at  P,  Fig.  37. 


172 


METALLURGY    OF    CAST    IRON. 


TABLE   24. 
RECORD    OF   TESTS    TAKEN    FROM    IRON    SEEN    IN    FIG.   37. 


No.  of  Bars. 

Size  of  Bars. 

Contraction. 

Chill. 

i 

K*_!M 

•293 

Nearly  white. 

2 

KXI^ 

.266 

tfdeep. 

3 

HXI# 

.242 

K  deep. 

4 

^XI^ 

.220 

3-16  deep. 

5 

HxiJ* 

.200 

3-16  deep. 

6 

&xiK 

.182 

%  deep. 

7 

%  x  \yz 

.165 

Ys  deep. 

8 

i   xij* 

.150 

3-32  deep. 

9 

i£xi# 

.148 

3-32  deep. 

TABLE    25. 
RECORD    OF   TESTS    TAKEN    FROM    IRON    SEEN   IN    FIG.   38. 


No.  of  Bars. 

Size  of  Bai  s. 

Contraction. 

Chill. 

, 

'/sxi^ 

.178 

.03  deep. 

2 

KxiJ* 

.163 

.02  deep. 

3 

#XlJ* 

.150 

.01  deep. 

4 

MXI^ 

•137 

Hardly  perceptible. 

5 

^8X1^ 

•  125 

No  chill. 

6 

KXI^ 

.112 

No  chill. 

7 

%XI^ 

.101 

No  chill. 

8 

I        X  1}^ 

.92 

No  chill. 

9 

1%  X  Ij< 

.88 

No  chill. 

This  chill  was  obtained  by  causing  the  end  of  the 
test  bars  farthest  from  the  gate  to  be  formed  by  a 
wrought  iron  bar  three-fourths  by  two  inches  wide. 
The  twelve  test  bars  of  each  set  were  molded  in  green 
sand  and  poured  from  one  gate.  The  same  '  *  temper  ' ' 
of  sand  was  used  for  both  flasks,  and  the  iron  was 
alike  in  fluidity  at  the  time  of  pouring.  Only  nine 
tests  out  of  each  of  the  twelve  bars  seen  in  Figs.  37 
and  38  are  given. 

To  further  demonstrate  the  deceptive  appearance  of 
fractures  in  pig  iron,  analyses  of  three  pieces  of  pig 


APPEARANCE    OF    THE    FRACTURE    OF    PIG    IRON.        173 


FIG.  40. — NO.  I  IRON  BY  FRACTURE,  BUT  NO.  8  BY  ANALYSIS. 


FIG.  41. — NO.  7  IRON  BY  FRACTURE,  BUT  NO.  4  BY  ANALYSIS. 


FIG.  42. — NO.  9  IRON  BY  FRACTURE,  BUT  NO,  I  BY  ANALYSIS. 


174 


METALLURGY    OF    CAST    IRON. 


samples  are  given  in  Table  26  and  illustrated  in  Figs. 
40,  41,  and  42. 

TABLE    26. — CHEMICAL   ANALYSES   OF    PIG    SPECIMENS. 


Fig. 

Silicon. 

Sulphur. 

Manganese. 

Phosphorus. 

40 
4i 
42 

.98 
1.82 
3-30 

.015 

.017 

•30 
•35 
•34 

.092 
.096 
.080 

The  author  has  numbered  the  above  irons  from  the 
appearance  of  their  fracture  and  not  from  the  chemical 
analysis,  as  an  iron  3.30  (Fig.  42)  in  silicon  with  sul- 
phur as  shown  would  prove  a  good  No.  i  iron  when 
re-melted,  but  the  fracture  would  assert  it  to  make  No. 
9  or  hard  iron.  Then  again,  in  judging  by  fracture  Fig. 

4 1  would  make  a  very  hard  iron,  while  Fig.  40  would  make 
a  very  soft  casting,  when  in  truth  the  reverse  results 
would  be  obtained  by  both  as  shown  by  the  analyses. 
It   will   be   seen  by  the  Table   26  that  the  chemical 
analyses  of  these  three  samples  are  practically  all  the 
same  excepting  in  the  silicon  contents.     The  author 
could  present  any  number  of  specimens  which  would 
be  as  deceptive  to  the  eye  in  judging  their  grade  by 
fractures,  etc. ,  but  what  is  given  in  this  chapter  should 
be  sufficient  to  illustrate  that  we  cannot  be  always 
correctly  guided  by  the  appearance  of  the  fracture  (or 
hardness  of  pig  iron,  as  treated  in  the  next  chapter)  to 
define  the  grade  of  iron  when  re-melted  or  poured  in 
castings.     The  pig  samples  seen  in  Figs.  40,  41  and 

42  are  numbered  after  the  method  advanced  in  table 
22,  page  152. 


CHAPTER  XXV. 

THE    IMPRACTICABILITY   OF   HARDNESS 
TESTS  FOR  GRADING  PIG  IRON. 

A  drill  test  was  advocated,  at  the  close  of  1900,  as 

being1  practical  to  define  the  grade  of  pig  iron  or  the 
degree  of  hardness  it  would  impart  to  castings.  There 
are  foundrymen  today  who  could  be  misled  into  believ- 
ing such  a  system  practical,  and  would  buy  the  machine 
advocated  for  this  work.  A  hardness  test  for  pig  iron 
is  no  more  or  less  than  judging  iron  by  the  appearance 
of  its  fracture,  a  method  which  has  been  in  vogue  for 
a  century  but  now  known  to  be  wholly  erroneous. 
There  are  two  ways  of  producing  different  degrees  of 
hardness  in  pig  iron  or  castings,  one  is  by  varying  the 
percentages  of  silicon,  sulphur,  manganese,  and  phos- 
phorus in  iron,  the  other  by  varying  the  rate  of  solidi- 
fication and  cooling  to  a  cold  state,  also  shown  on  pages 
167  and  1 68.  Alterations  in  either  of  these  factors  can 
cause  the  carbon  to  take  the  combined  or  graphitic 
form.  The  higher  the  combined  carbon  the  harder 
the  iron,  and  the  more  the  graphitic  carbon  is  in 
evidence  the  softer  the  iron. 

An  illustration  of  what  may  often  be  expected  in  the 
differences  of  hardness  between  two  casts  of  pig  iron 
that  would  give  like  grades  or  softness  in  like  castings, 
is  seen  in  Nos.  i  and  2,  Fig.  43.  Were  these  samples 


176  METALLURGY    OF    CAST    IRON. 

tested  for  hardness  they  would  be  found  so  different 
that  anyone,  guided  by  hardness  tests,  would  say  that 
No.  i  would  make  a  very  soft  casting  while  No.  2 
would  make  a  very  hard  one,  when  in  fact  each  will 
give  like  softness  in  like  castings  and  treatment  in 
cooling.  These  samples  were  drilled  with  a  press  run- 
ning at  uniform  speed  and  pressure.  It  took  eight 
minutes  to  drill  No.  i  and  twenty-two  minutes  to  drill 
No.  2,  a  difference  of  fourteen  minutes.  A  half -inch 
twist  drill  .was  used  and  the  method  of  drilling  will  be 
seen  by  the  half  holes  on  the  back  of  the  specimen  seen 
in  No.  3.  The  difference  in  the  hardness  of  these 
samples,  it  is  to  be  remembered,  is  found  in  samples 
of  like  analysis,  excepting  in  combined  carbon  and  in 
iron,  coming  from  the  same  tap  and  cast  in  sand 
moulds.  As  long  as  uniformity  in  making  iron  cannot 
be  achieved,  as  is  illustrated  in  Chapter  XXIV.,  we 
may  expect  that  the  state  of  the  carbon  or  hardness  of 
pig  iron  will  vary,  and  often  not  be  in  accordance  with 
the  grade  results  as  shown  by  the  percentages  of 
silicon,  sulphur,  manganese,  and  phosphorus  which 
will  be  in  the  pig  iron.  It  will  appear  ridiculous  to 
those  who  know,  by  experience  and  research,  the 
deceptive  nature  of  the  appearance  and  hardness  of 
sand-cast  pigs  that  any  one  should  now,  at  this  day  of 
advancement  in  the  metallurgy  of  cast  iron,  try  to 
introduce  a  hardness  test  to  define  the  grade  of  pig 
iron  as  now  being  generally  cast. 

It  is  not  to  be  understood  that  every  cast  of  pig 
metal  is  deceptive  to  the  eye,  or  hardness  test.  It  may 
be  that  three-fourths  of  all  the  iron  cast  at  some 
furnaces  may  possess  a  true  fracture  of  hardness  or 
accord  with  the  amount  of  silicon,  sulphur,  etc.,  an 


IMPRACTICABILITY  OF  HARDNESS  TESTS  FOR  PIG  IRON.     177 


II 

c   o 

K  5 
^ 

S 

en 

W      H 


178  METALLURGY    OF    CAST    IRON. 

iron  contains.  Then  again,  it  may  be  that  nine-tenths 
of  all  casts  would  possess  true  fractures  of  hardness. 
Even  if  this  latter  were  so,  are  we  not  justified  in  con- 
demning the  practice  of  being  guided  by  the  appearance 
of  fractures  or  hardness,  especially  when  there  exists 
another  method  (chemical  analysis)  which  is  known  to  be 
positively  correct  in  defining  the  grade  of  any  brand  of 
iron  every  time  it  is  employed?  At  the  best,  what  sense 
is  there  of  any  foundryman  taking  chances  of  having 
one  out  of  ten  heats  result  in  wrong  grades  of  iron  in 
his  castings  when,  by  following  chemical  analyses,  he 
can  have  not  only  all  his  heats  acceptable  but  also  have 
them  far  nearer  the  grade  he  desires  than  is  ever  pos- 
sible by  being  guided  by  fractures  or  hardness? 

From  careful  observation  in  contrasting  appearances 
of  fractures  with  chemical  analysis,  with  heats  melting 
from  70  to  100  tons,  the  author  can  say  that  fully  one- 
half  of  the  furnace  casts  of  pig  which  he  used  would 
have  given  him  grades  of  iron  different  than  what  he 
desired  in  his  castings,  and  some  of  the  heats  would 
have  been  practically  worthless  and  caused  a  loss  of 
much  money  and  trade,  had  he  been  guided  by  the 
old-school  method  of  judging  by  fracture  or  hardness. 
From  the  author's  observation  and  experience,  he 
believes  it  safe  to  say  that  from  a  third  to  half  of  the 
iron  made  will  not,  at  the  present  day,  agree  in  the 
appearance  of  fracture  or  hardness  with  the  analysis. 
The  margin  that  some  founders  possess  in  having  their 
castings  accepted  when  the  grade  of  iron  is  not  what 
it  should  be,  causes  them  to  often  be  indifferent  in 
exacting  the  best  obtainable.  However,  the  day  is 
coming  when  such  practice  will  not  be  tolerated  and 
all  founders  will,  as  a  rule,  be  forced  by  competition  to 


IMPRACTICABILITY  OF  HARDNESS  TESTS  FOR  PIG  IRON.     179 

obtain  that  which  is  best  to  exist  in  their  castings  as 
nearly  as  possible.  When  'this  day  arrives  we  will 
hear  no  more  of  being  guided  by  the  appearance  of 
fractures  or  hardness,  unless,  by  better  regulation  of 
furnace  workings  and  the  casting  of  metal  from  ladles 
into  iron  chill  moulds  may,  in  years  to  come,  cause  the 
appearance  and  hardness  of  fractures  to  agree  with  the 
chemical  analysis ;  but  this  is  doubtful  of  achievement 
to  the  perfection  that  should  be  obtained. 

In  the  "  Foundry  "  of  November,  1901,  a  statement  Is  made, 
under  the  head  of  "  Cast  Iron  Notes,"  inferring  that  two  furnace 
casts  of  gray  pig  iron  of  the  same  analyses  and  brand,  but  of 
different  grain  or  fracture^would  give  a  different  grade  or  charac- 
ter of  iron  in  like  castings.  This  is  practically  the  same  as 
thinking  to  correctly  judge  pig  iron  by  its  hardness,  as,  in  either 
case,  the  hard  or  close  grained  pig  has  more  combined  carbon 
than  the  soft  or  open  grained  pig  and  as  a  fact,  the  samples  Nos. 
i  and  2,  Fig.  43,  are  of  like  analyses,  excepting  the  graphitic  and 
combined  carbon,  but,  if  remelted  under  like  conditions,  as  could 
be  done  in  the  cupola  shown  on  page  241,  castings  of  like  softness 
would  be  produced ;  at  least,  so  close  that  there  would  require  to 
be  a  much  more  radical  difference  in  the  grain  of  two  furnace 
casts,  of  like  analyses  in  the  same  brand,  than  is  shown  by  the 
samples  Nos.  I  and  2,  Fig.  43.  The  difference  that  a  very  open 
and  very  close  grained  iron  of  the  same  analyses  and  brand  could 
make  would  be  in  the  most  close  grained  iron  giving  a  slightly 
softer  casting  than  the  open  iron,  after  the  principles  presented 
in  Chapter  47,  pages  337  to  339.  However,  there  is  no  reason 
why  any  one  should  make  it  a  point  to  insist  on  accepting  only 
open  or  close  grained  iron  in  connection  with  exacting  any  certain 
specified  analyses  from  blast  furnaces,  as  the  slight  difference 
possible  in  the  most  radical  cases  of  open  and  close  grained  iron 
can  be  regulated  by  a  slight  variation  in  silicon  when  making  a 
mixture,  and  which  anyone  can  easily  do,  if  they  so  desire. 


CHAPTER  XXVI. 

ORIGIN    AND     UTILITY    OF    STANDARD- 
IZED DRILLINGS. 

To  test  the  practicability  of  obtaining  uniform  anal- 
yses of  one  quarter  piece  of  pig  iron,  samples 
of  well  mixed  pig  drillings  were  sent  out  by 
the  author,  during  the  summer  of  1897,  to  twenty 
leading  chemists  in  different  parts  of  the  country  to  be 
analyzed,  with  a  view  of  ascertaining  how  closely  their 
results  would  agree.  The  reports  were  such  as  were 
anticipated.  No  two  were  alike,  and  the  difference 
between  the  extremes  was  so  great  that  a  founder 
being  guided  by  one  extreme,  in  forming  a  comparative 
measure  for  making  mixtures,  could,  should  he  accept 
the  other,  sustain  great  losses,  or  obtain  a  grade  of 
metal  far  different  than  what  should  exist  in  his  cast- 
ings. The  evil  results  obtained  from  such  variations 
of  analysis  were  such  as  to  prevent  chemistry  ever 
being  universally  established  in  founding.  Exhibiting 
the  weakness  of  chemical  methods,  as  did  the  author 
by  the  publication  of  the  reports  obtained,  caused 
another  party  to  send  out  samples  of  drillings  to  fifty 
chemists  with  the  view  of  getting  better  results. 
No.  i  of  Table  27  shows  the  difference  in  the  great- 
est variations  of  the  analyses  reported  to  the  author, 
and  No.  2  shows  the  greatest  variation  in  the  analy- 
ses obtained  by  the  second  party: 


ORIGIN  AND  UTILITY  OF  STANDARDIZED  DRILLINGS.     l8l 
TABLE   27. 


Sil. 

Sul. 

Phos. 

Mang. 

C.  C. 

G.  C. 

T.  C. 

Variation  i 

.19 

.028 

.029 

.19 

•34 

.82 

.48 

Variation  2 

.21 

.015 

.031 

.23 

•59 

•77 

1.09 

Those  making  a  study  of  the  reasons  for  such  differ- 
ences in  results  as  shown  by  Table  27,  will  find  that  it 
is  due  to  the  fact  that  chemists  are  unable  to  know 
positively  the  correctness  of  their  results  without 
checking1  them  by  some  known  standard.  Almost 
every  trade  possesses  some  standard  by  which  its  arti- 
sans can  tell  whether  their  labors  have  been  productive 
of  the  perfection  desired.  The  appearance  of  the 
finished  casting  indicates  to  the  furnaceman  or  founder 
the  result  obtained  from  his  iron.  A  trial  of  a  machine 
or  an  engine  demonstrates  to  the  machinist  or  engineer 
the  perfection  he  has  attained,  but  the  completion  of 
an  analysis  by  a  chemist  presents  no  tangible  evidence 
of  the  accuracy  of  his  results.  The  only  way  a  chem- 
ist can  know  the  correctness  of  his  results,  or  give 
others  any  assurance  that  his  work  is  correct,  is  by 
having  them  checked  by  others,  or  by  analyzing  stand- 
ardized drillings  that  have  been  determined  by  com- 
petent chemists  to  find  whether  results  agree.  The 
latter  method  of  checking  is  similar  to  the  use  of 
standard  weights  to  test  the  accuracy  of  scales.  No 
laboratory  is  complete  without  its  standardized  drill- 
ings, any  more  than  would  be  a  furnace  or  foundry 
without  standard  weights  for  occasional  testing"  of 
scales.  This  necessity  has  led  many  chemists  here- 
tofore to  make  their  own  standards.  An  observing 
person  having  the  opportunity  to  visit  chemical  labor- 


1 82  METALLURGY    OF    CAST    IRON. 

atories  would  often  find  the  chemist  using  these 
standards,  to  test  chemicals,  short-cut  methods,  or 
the  correctness  of  results  that  had  been  questioned. 
The  process  by  which  individual  chemists  obtained 
their  own  standards  was,  as  a  rule,  long-  and  tedious. 
It  often  took  from  four  to  six  months  to  get  in  all  the 
results.  Then  again,  as  a  rule  the  results  varied  so 
much  that  the  average  accepted  for  a  standard  seemed 
more  like  guesswork  than  the  result  of  accurate  work 
and  methods.  The  variation  in  analyses  thus  obtained 
has  often  caused  great  difference  in  standards  in  use 
in  different  circles  and  perplexed  managers  of  steel 
works,  furnaces,  founders,  and  chemists  rather  than 
helped  them  to  correct  evils  and  prevent  losses.  It 
was  the  opportunity  of  observing  the  practice  of  blast 
furnace  chemists  making  their  own  standards  that 
caused  the  author  to  conceive  the  idea  of  one  central 
agency,  from  which  all  could  obtain  standardized  drill- 
ings, which  had  been  determined  by  a  few  of  our  best 
known  chemists. 

After  devising  a  plan  for  a  central  agency  or  bureau 
for  the  distribution  of  standardized  drillings,  the  author 
presented  a  paper  to  the  Pittsburg  Foundry  men's 
Association,  April  25,  1898,  setting  forth  the  need  of 
greater  uniformity  in  analysis  and  suggesting,  in 
outline,  his  plan  for  establishing  a  central  agency. 
At  this  meeting  a  committee  was  appointed  with  the 
author  as  chairman  to  introduce  the  project  before  the 
American  Foundrymen's  Association  at  Cincinnati, 
June,  1898.  This  convention  unanimously  approved 
the  project,  and  appointed  a  committee  to  proceed  with 
the  work.  This  committee  consisted  of  Dr.  Richard 
Moldenke,  now  secretary  of  the  A.  F.  A.,  New 


ORIGIN   AND  UTILITY  OF  STANDARDIZED  DRILLINGS.     183 

York;  James  Scott,  superintendent  of  the  Lucy 
Furnace,  Pittsburg;  P.  W.  Gates,  president  of  the 
Gates  Iron  Works,  Chicago,  and  E.  H.  Putnam,  super- 
intendent of  the  Moline  Plow  Works,  Moline,  111. ,  with 
the  author  as  chairman.  The  appointment  of  the 
committee  gave  a  sound  basis  on  which  to  work,  but 
the  importance  of  the  reform  and  the  obstacles  which 
had  to  be  overcome  before  the  same  could  be  estab- 
lished were  realized  by  but  few.  The  first  work  of 
the  committee  was  to  adopt  the  plans  advanced  by  the 
author  in  his  paper  before  the  Pittsburg  Foundry- 
men's  Association,  April,  1898,  and  which  secured  for 
us  the  services  of  Prof.  C.  H.  Benjamin  to  supervise 
the  work  of  making  the  drillings,  and  of  Prof.  A.  W. 
Smith  to  carry  forward  the  work  of  preparing,  stand- 
ardizing, and  packing  the  samples ;  also,  the  services 
of  Booth,  Garrett  &  Blair,  Andrew  S.  McCreath, 
Cremer  &  Bicknell  to  analyze  the  drillings,  the  average 
of  the  four  results  being  accepted  as  a  standard. 

One  of  the  greatest  obstacles  in  the  way  of  estab- 
lishing and  maintaining  a  central  standardizing  agency 
lay  in  the  difficulty  of  obtaining  a  sufficient  amount  of 
uniform  turnings  or  drillings  from  one  sample  of  iron, 
free  of  sand,  grit,  slag,  etc.,  to  permit  all  laboratories 
to  obtain  a  pound  or  more  of  them.  As  a  rule,  chem- 
ists have  found  it  difficult  to  obtain  twenty-five  pounds 
of  clean,  uniform,  and  reliable  samples.  A  study  of 
this  phase  of  the  subject  will  show  that  the  practica- 
bility of  establishing  and  maintaining  a  central  stand- 
ardizing bureau  is  largely  dependent  upon  the  ability 
of  the  founder  to  make  large  castings  weighing  five 
hundred  pounds  or  more,  from  which  could  be  obtained 
a  large  amount  of  clean,  uniform  drillings.  For  this 


184     .  METALLURGY    OF    CAST    IRON. 

reason,  a  well-known  writer  has  aptly  said  that  the 
establishing  and  maintaining  of  a  central  standardizing 
agency  is  properly  foundry  men's  work.  As  the  mak- 
ing of  these  castings  involves  principles  of  founding 
interesting  to  many,  we  illustrate  the  plan  used,  which 
is  as  follows :  A  mold  of  dry  sand,  for  the  outer  body 
and  a  dried  core  for  the  inner,  are  made  as  seen  in  the 
plan  and  section  view  of  Figs.  44  and  46.  The  con- 
struction of  the  mold  explains  itself.  The  secret  of 
getting  a  clean,  solid  casting  lies  mainly  in  the  method 
of  gating  and  pouring  it.  At  A  is  a  gate  leading  down 
to  the  bottom  of  the  mold  at  an  inlet  at  D.  The 
round  gates  B,  seen  at  the  top  of  the  mold,  are  placed 
about  four  inches  apart  and  are  one -half  inch  in  diam- 
eter. A  riser  is  seen  at  E.  In  starting  to  pour  the 
mould,  the  molten  metal  is  directed  to  drop  from  the 
ladle  into  the  basin  at  the  point  marked  W,  in  a  way 
that  will  allow  it  to  flow  gently  down  the  gate  A  and 
enter  the  mould  at  D  to  prevent  the  bottom  being  cut 
by  the  top  gates.  When  from  thirty  to  fifty  pounds 
of  metal  has  entered  the  mould,  a  quick  turn  of  the 
ladle  empties  a  large  body  of  the  metal  into  the  pour- 
ing basin,  quickly  filling  all  the  gates  at  B ;  this  then 
drops  the  metal  down  upon  that  which  is  rising  from 
the  stream  flowing  in  at  D.  This  action  is  kept  up 
until  the  mould  is  filled  and  the  metal  runs  out  at  the 
riser  E.  After  this  point  is  attained,  the  pouring  is 
slackened  and  a  steady  stream  maintained  until  from 
three  hundred  to  five  hundred  pounds  of  metal  has 
flown  through  the  riser  E  to  run  down  the  incline  seen 
at  S  into  the  scrap  hole  X.  .  The  effect  of  allowing 
such  a  large  body  of  metal  to  flow  through  the  mould 
by  making  it  enter  the  gate  at  A  is  to  keep  up  an  agita- 


ORIGIN  AND  UTILITY  OF  STANDARDIZED  DRILLINGS.     185 


tion  after  the  mould  has  been  filled,  which  in  turn  is 
most  beneficial  in  causing  the  metal  in  the  mould  to 
mix  ^vvell  and  counteract  variations  in  structure  that 
might  otherwise  take  place.  The  metal  dropping 


^  x 


FIG.  46. 

from  the  top  gates  B  causes  a  disintegrating  action, 
cutting  into  fine  particles  any  dirt  that  might  accumu- 
late upon  the  surface  of  the  rising  metal,  and  which,  were 
it  not  thus  chopped  up,  as  it  were,  into  fine  particles, 
would  gather  in  large  lumps  and  be  caught  and  held 
fast  in  the  mold  walls,  with  the  result  that  dirt  spots, 


l86  METALLURGY    OF    CAST    IRON. 

etc.,  would  be  found  in  the  casting  when  the  skin  was 
removed  by  a  drill,  lathe,  or  planer.  Again,  the  fact 
that  the  metal  drops  from  the  top  of  the  mold  besides 
entering  at  the  bottom,  causes  the  top  body  of  the 
rising  metal  to  be  as  fluid  as  that  at  the  bottom,  which 
is  also  beneficial  in  causing  all  scum  and  dirt  to  float 
upward  with  the  metal  to  the  top  of  the  mold  or 
"  riser  head."  Where  metal  fills  a  mold  all  from  the 
bottom  it  becomes  rapidly  duller  in  rising  to  fill  the 
mould  and  can  leave  dirt  scattered  throughout  the 
casting,  an  evil  which  will  be  readily  seen.  Fig.  45 
shows  a  section  of  the  casting  obtained  from  the 
mould,  with  the  exception  of  four  lugs  cast  on  to  assist 
in  holding  the  cylinder  or  casting  in  the  lathe  while  it 
is  being  turned.  It  will  be  well  to  state  that  there  is 
no  difficulty  in  obtaining  castings  weighing  tons  which 
might  serve  for  standardizing  purposes,  if  cast  upon 
the  principles  herein  described.  Before  starting  to 
make  these  castings,  investigations  were  made  as  to 
the  variations  in  metalloids  most  likely  to  be  demanded 
by  the  trade  in  general.  It  was  found  that  samples 
high,  medium,  and  low  in  silicon,  sulphur,  manganese, 
and  phosphorus  would  satisfy  most  of  our  country's 
laboratories  as  far  as  iron  standards  were  concerned. 
To  obtain  this  variety  of  standards  called  for  the  mak- 
ing of  three  distinct  castings  of  different  grades  of  iron. 
These  were  cast  with  iron  melted  in  a  small  cupola, 
under  the  direction  of  the  author,  at  the  Thos.  D.  West 
Foundry  Co.,  after  the  plan  herein  described. 

To  obtain  the  turnings  or  drillings,  which  had  to  be 
fine  enough  to  pass  a  2o-mesh  sieve,  was  no  easy  mat- 
ter and  rather  a  costly  affair.  To  get  one  pound  of 
drillings  per  hour  was  thought  to  be  good  work.  The 


ORIGIN  AND  UTILITY  OF  STANDARDIZED  DRILLINGS.     187 

plan  of  securing  these  turnings  or  drillings  was  first  to 
take  off  about  one-eighth  of  an  inch  from  the  surface 
of  the  casting.  These  first  turnings  were  cast  aside, 
as  they  contained  more  or  less  scale  or  refuse  formed 
on  the  surface  of  the  casting  by  the  fusing  action  of 
the  molten  metal  upon  the  sand  forming  the  face  of 
the  mould.  After  this  surface  had  been  turned  off 
and  all  debris  removed  carefully  from  the  lathe,  the 
cylinder  was  turned  until  about  a  one-quarter  inch 
thickness  of  the  inner  shell  remained.  The  turnings 
obtained  from  the  body  after  the  one-eighth  inch 
thickness  was  removed  from  the  surface  were  the  ones 
taken  for  standardizing  purposes.  It  should  be  stated 
that  about  a  one-half  inch  thickness  at  the  botom  and  the 
''riser  head"  of  two  inches  at  the  top  were  not  disturbed, 
so  as  not  to  have  the  scale  on  the  bottom  of  the  casting, 
or  any  dirt  that  would  be  collected  at  the  top  end 
mixed  with  the  turnings  obtained  from  the  inner  body 
of  the  casting.  After  the  turnings  had  been  thus 
obtained  they  were  passed  through  a  20-  and  4o-mesh 
sieve.  This  done,  the  drillings  were  then  spread  out 
on  a  large  carbonized  cloth  and  thoroughly  mixed. 
The  mixing  having  been  perfected,  bottles  holding 
one-third  of  a  pound  were  placed  in  convenient  posi- 
tion and  filled  with  the  drillings,  by  having  a  scoop 
holding  sufficient  drillings  to  give  each  bottle  an  equal 
portion  from  every  filling  of  the  scoop.  In  filling  the 
scoop,  drillings  are  taken  from  different  parts  of  the 
spread  so  that  all  bottles  will  contain  some  of  every 
portion  of  the  drillings.  Repeated  analyses  of  differ- 
ent bottles  or  samples  have  proved  the  mixing  to  be 
all  that  could  be  desired. 

The  samples  made  up  to  1902  are  designated  as  A,  B, 


1 88  METALLURGY    OF    CAST    IRON. 

C,  and  D.  Sample  A,  which  has  been  ground  to  pass 
a  4o-mesh  sieve,  gives  one  total,  combined  carbon  and 
one  graphite.  Sample  B  gives  a  low  silicon,  a  medium 
sulphur,  a  low  manganese,  a  phosphorus  which  is 
within  the  Bessemer  limit,  and  a  titanium.  This  has 
been  passed  through  a  2o-mesh  sieve.  Sample  C  gives 
a  medium  silicon,  high  sulphur,  medium  manganese, 
medium  phosphorus,  and  a  titanium.  This  has  also 
passed  a  2o-mesh  sieve.  Sample  D  gives  a  high  silicon, 
low  sulphur,  high  manganese,  and  high  phosphorus, 
and  has  passed  through  a  4o-mesh  sieve. 

The  standards  are  sold  at  the  price  of  $5.00  per 
pound  (a  discount  of  40  per  cent,  is  allowed  to  colleges 
and  dealers),  and  in  no  instance  will  less  than  one 
pound  be  sold.  The  samples  are  packed  in  bottles 
holding  one-third  of  a  pound  and  delivered  in  cases, 
as  illustrated  on  page  189,  holding  three  or  four  bottles 
according  to  the  desires  of  a  subscriber.  One  pound 
of  the  samples  should  furnish  enough  material  for  36 
complete  analyses,  or  at  least  200  separate  determina- 
tions. The  exact  analyses  of  the  samples  A,  B,  C,  and 
D  are  sent  separately  by  mail,  so  that  they  may  be 
placed  upon  bottles  or  kept  private,  as  desired  by  the 
subscriber. 

By  addressing  any  member  of  the  committee  (see 
page  183),  all  orders  for  drillings  will  receive  prompt 
attention.  Money  may  accompany  orders  or  be  sent 
after  receipt  of  drillings,  as  best  suits  the  pleasure  of 
the  buyer. 

To  secure  the  first  orders  for  standardized  drillings, 
the  author  found  it  necessary  to  call  upon  many 
managers  and  chemists  at  their  offices,  but  the 
good  work  once  well  under  way  advanced  so  rapidly 


Sample «!  Cast  Iron 


FIG.  47. 


190  METALLURGY    OF    CAST    IRON. 

that  today  (Oct.,  1901)  we  have  over  two  hundred 
laboratories  in  this  country  and  in  Europe  using  these 
standardized  drillings.  To  show  the  character  of 
concerns  using  these  standards,  we  publish  the 
following  list  in  alphabetical  order,  followed  by 
extracts  from  a  few  of  many  testimonials  in  the  pos- 
session of  the  author,  which  indicate  the  success  of  the 
work  and  the  esteem  in  which  it  is  held : 

Ashland  Coal,  Iron  &  Railway  Co.,  Andrew  Brothers  Co.,  Alle- 
gheny Iron  Co.,  Alabama  Consolidated  Coal  &  Iron  Co.,  Andover 
Iron  Co.,  Ashland  Steel  Co.,  Atlanta  Iron  &  Steel  Co.,  Allentown 
Rolling  Mill  Co.,  Air  Brake  Co.,  New  York;  Atlantic  Iron  & 
Steel  Co.,  Bellefonte  Furnace  Co.,  Brier  Hill  Iron  &  Coal  Co., 
Buffalo  Iron  Co.,  E.  &  G.  Brooks  Iron  Co.,  Bethlehem  Iron  Co., 
Bell  City  Malleable  Iron  Co.,  Builders'  Iron  Foundry  Co.,  Lucius 
Brown,  Blodgett,  Britton  &  Co.,  Boulder  University,  Burgess 
Steel  &  Iron  Works,  Bellaire  Works,  National  Steel  Co.,  Canada 
Iron  Furnace  Co.  (Radner  Forges  and  Midland),  Colonial  Iron 
Co.,  Chickies  Iron  Foundry,  Carbon  Steel  Co.,  Carbon  Iron  & 
Steel  Co.,  Camden  Iron  Works,  Carteret  Steel  Co.,  Carnegie  Steel 
Co.,  Chicago  &  Burlington  Railway,  Clinton  Iron  &  Steel  Co., 
James  Clow  &  Sons,  William  Cramp  &  Sons,  J.  I.  Case  T.  M.  Co., 
Cooper  Union,  Cornell  University,  Columbia  University,  Dunbar 
Furnace  Co.,  Danville  Bessemer  Co.,  Dora  Furnace  Co.,  Deutsche 
Niles-Werzeugmasschinen-Fabrik,  Draper  Co.,  Dickmen  &  Mc- 
Kensie,  Dayton  Coal  &  Iron  Co.,  Deseronto  Iron  Co.,  Everett 
Furnace  Co.,  Embreville  Iron  Co.,  Elk's  Rapid  Iron  Co.,  Emma 
Furnace,  Empire  Steel  &  Iron  Co.,  Eimer  &  Amend  (four  labora- 
tories), F.  A.  Emmerton,  Franklin  Iron  Works,  Farrell  Foundry  & 
Machine  Co.,  Davenport  Fischer,  Frank-Kneeland  Machine  Co., 
Fort  Wayne  High  School,  The  Falk  Co.,  Girard  Iron  Co.,  Gates 
Iron  Works,  E.  Grindrod,  M.  A.  Hanna  &  Co.,  Hamilton  Blast 
Furnace  Co.,  Heckscher  &  Sons,  Hecla  Works,  England;  R.  C. 
Hindley,  M.  Hoskins,  Harvard  College,  Havemeyer  University, 
Henry  Hiels  Chemical  Co.,  Isabella  Furnace,  Iron  Gate  Furnace, 
Iroquois  Iron  Co.,  Illinois  Steel  Co.,  Jefferson  Iron  Co.,  Kittan- 
ning  Iron  &  Steel  Co.,  C.  A.  Kelly  Plow  Co.,  Lebanon  Furnace, 
Longdale  Iron  Co.,  Lacka wanna  Iron  &  Steel  Co.,  Logan  Iron 


ORIGIN  AND  UTILITY  OF  STANDARDIZED  DRILLINGS.     19 1 

Mfg.  Co.,  C.  E.  Linebarger,  Ludw.  Loewe  &  Co.,  Berlin;  Lehigh 
University,  A.  R.  Ludlow,  Lowmoor  Iron  Co.,  Minerva  Pig  Iron 
Co.,  Missouri  Furnace  Co.,  Monongahela  Furnace  Co.,  Mable 
Furnace  Co.,  S.  McCreath,  McNary  &  DeCamp  Co.,  Martin  Iron 
&  Steel  Co.,  Missouri  Malleable  Iron  Co.,  McConway  &  Torley 
Co.,  C.  F.  McKinney,  J.  McGavok,  Massachusetts  Institute  of 
Technology,  Michigan  School  of  Mines,  Northwestern  Iron  Co., 
New  River  Mineral  Co.,  Noyes  Bros.,  Sydney,  Australia;  Nova 
Scotia  Steel  Co.,  Niagara  University;  Nicopol,  Mariopol,  Sar- 
tana,  Russia ;  Ohio  Iron  &  Steel  Co. ,  Oil  City  Boiler  Works,  Ohio 
State  University,  Pickands,  Mather  &  Co.,  Penn  Iron  &  Steel 
Co.,  Pioneer  Mining  &  Mfg.  Co.,  Pennsylvania  Steel  Co.,  Penn- 
sylvania Malleable  Co.,  Pittsburg  Locomotive  &  Car  Works, 
Purdue  University,  Pioneer  Iron  Co.,  Princess  Iron  Co.,  Punxu- 
tawney  Iron  Co. ,  River  Furnace  &  Dock  Co. ,  Reading  Iron  Co. , 
Rome  Testing  Laboratory,  Sharpsville  Furnace  Co.,  Spearmand 
Iron  Co.,  Stewart  Iron  Co.,  Salem  Iron  Co.,  Shickle,  Harrison  & 
Howard  Co.,  Sharon  Iron  Works,  Sloss  Iron  &  Steel  Co.,  Syra- 
cuse Chill  Plow  Co.,  Snow  Steam  Pump  Co.,  Sargent  Co.,  M. 
Strong,  O.  Sowers,  W.  M.  Sanders,  Stevens  Institute  of  Technol- 
ogy, D.  A.  Sandburn,  Tennessee  Coal,  Iron  &  Railroad  Co., 
Towanda  Iron  &  Steel  Co.,  Thomas  Iron  Co.,  E.  Tonseda,  Union 
Iron  &  Steel  Co.,  Union  Iron  Works,  United  States  Cast  Iron  & 
Foundry  Co.  (three  laboratories),  University  of  Buffalo,  Univer- 
sity of  Pennsylvania,  University  of  Michigan,  University  of  Min- 
nesota, Virginia  Iron,  Coal  &  Coke  Co.,  Virginia  Polytechnical 
Institute,  Warwick  Iron  Co.,  Woodward  Iron  Co.,  Watt  Iron  & 
Steel  Co.,  D.  Woodman,  E.  J.  Wheeler,  Wooster  Polytechnical 
Institute,  Webster  University,  Westinghouse  Machine  Co., 
Wisconsin  Malleable  Iron  Co.,  Westinghouse  Air  Brake  Co., 
Youngstown  Steel  Co.,  Yale  University. 


192  METALLURGY    OF    CAST    IRON. 


EXTRACTS  OF  TESTIMONIALS  IN  PRAISE 
OF  STANDARDIZED  DRILLINGS. 

"  We  take  pleasure  in  saying  that  our  chemist  states  he  has 
used  the  standardized  drillings  in  standardizing  solutions  and 
found  them  to  be  very  exact ;  and  adds  that  too  much  praise 
cannot  be  accorded  the  standardized  drillings  you  recently  sent 
us. 

ELK  RAPIDS  IRON  Co., 
H.  B.  Lewis,  Pres." 

"  It  is  no  little  comfort  to  have  the  standardized  samples  and 
to  know  that  the  work  of  our  laboratory  is  correct  and  reliable. 

EDGAR  S.  COOK, 
Pres.  Warwick  Iron  Co.,  Pottstown,  Pa." 

"  We  are  pleased  with  samples.     They  will,  without  doubt, 
greatly  promote  increasing  accuracy  in  methods  of  iron  analysis. 
J.  BLODGET  BRITTON  Co.,  Warrentown,  Va." 

"  We  are  using  the  standardized  drillings  and  find  them  very 
useful  in  our  laboratory.  We  think  it  very  necessary  that  labora- 
tories should  be  supplied  with  standardized  drillings,  especially 
those  working  on  blast  furnace  products.  L.  C.  PHIPPS, 

Second  Vice-president  Carnegie  Steel  Co.,  Pittsburg,  Pa." 

"  It  has  always  been  a  task  to  get  standards,  especially  stand- 
ards that  would  check  up  with  those  from  different  concerns.  It 
will  simplify  matters  considerably  if  chemists  will  use  standards 
from  one  "party  of  the  same  value,  as  I  have  found  that  most  of 
the  errors  in  sulphur  and  phosphorus  come  from  different  chem- 
ists' standards  not  checking.  J.  O.  MATHERSON,  Chemist, 
Ashland  Coal,  Iron  &  Railway  Co. ' ' 

"  I  think  the  method  of  selling  standardized  iron  samples  from 
a  central  laboratory,  such  as  the  Standardizing  Bureau  of  the 
American  Foundrymen's  Association,  is  one  to  be  commended. 
The  confidence  I  have  in  my  work  after  checking  with  these  drill- 
ings is  very  gratifying.  WALTER  M.  SAUNDERS, 
Analytical  and  Consulting  Chemist,  Providence,  R.  I." 


ORIGIN   AND  UTILITY  OF  STANDARDIZED  DRILLINGS.      193 

"  In  connection  with  the  use  of  the  standardized  drillings,  I 
wish  to  say  that  I  believe  ^he  plan  will  result  in  attaining  greater 
accuracy,  will  inspire  confidence,  and  will  enhance  the  value  of 
analytical  chemical  work  in  connection  with  foundry  practice. 

W.    P.    RlCKELLS, 

Columbia  University." 

"  The  standard  samples  are  a  grand  idea  and  the  confidence 
they  impart  is  worth  ten  times  the  cost.  W.  G.  SCOTT.  ' ' 

"  I  have  noticed  with  pleasure  your  praiseworthy  efforts  to 
establish  uniformity  in  pig  iron  analysis.  .  .  .  Thanking 
you  for  your  endeavors  to  mitigate  the  perplexities  of  both  the 
furnace  manager  and  the  chemist,  JOHN  P.  MARSHALL, 

Supt.  Missouri  Furnace,  Carondelet." 

"  It  is  the  greatest  move  for  improvement  in  many  years. 

ERASTUS  C.  WHEELER," 

"  We  have  checked  our  routine  laboratory  work  from  time  to 
time  since  receipt  of  drillings  and  have  found  them  to  be  of  ines- 
timable value  to  us.  KlTTANNING  IRON  &  STEEL  MFG.  Co., 

W.  L.  Scott,  Chemist." 

'*  Permit  me  to  express  my  belief  that  this  work  of  your  asso- 
ciation of  distributing  carefully  analyzed  samples  of  pig  iron  is 
of  great  value  to  the  metallurgists  and  chemists  of  this  country. 

H.  L.  MILLS, 

Professor    Analytical  Chemistry,   Sheffield   Scientific   School  of 
Yale  University." 


CHAPTER  XXVII. 

INTELLIGENT     PURCHASE     AND     SAMP- 
LING  OF  PIG  IRON. 

There  were  comparatively  few  founders  using 
chemical  analysis  in  making  mixtures  of  cast  iron  when 
the  first  edition  of  this  work  appeared,  in  1897.  At  this 
time,  Oct.,  1901,  about  three-fourths  of  the  founders  are 
dependent  upon  a  knowledge  of  the  chemical  constit- 
uents of  their  pig  irons,  and  ignore  the  appearance  of 
fractures  or  hardness  of  pig  iron.  There  have  been 
some  ups  and  downs  in  the  experience  of  founders 
working  up  to  the  present  advancement.  Neverthe- 
less, as  founders  come  to  intelligently  understand  the 
science  of,  and  methods  necessary  to  be  followed  in 
working  by  chemical  analysis,  they  become  adherents 
of  its  practice.  One  great  drawback  has  been  in  the 
evils  resulting  from  practices  described  in  Chapters 
XIX.  and  XXIV.,  and  in  the  fact  of  depending 
wholly  upon  furnace  reports  of  chemical  analysis  which 
would  sometimes  prove  erroneous  by  reason  of  mis- 
takes, and  cause  beginners,  in  trying  to  utilize 
chemical  analyses  to  make  mixtures,  condemn  the  plan 
of  working  by  analysis. 

It  is  not  safe,  as  a  rule,  to  depend  wholly  upon  fur- 
nace reports  of  analyses,  for  the  reason  that  there  are 
several  chances  for  mistakes  being  made  aside  from 
what  the  chemists  might  make.  These  are  mistakes 


PURCHASE    AND    SAMPLING    OF    PIG    IRON.  195 

that  may  be  made  in  numbering  iron  piles,  transferring 
records  of  analyses  from  one  book  to  another,  etc., 
and  in  incorrectly  carding  the  cars  when  shipping  the 
iron  to  consumers.  The  author,  being  surrounded  by 
blast  furnaces,  has  seen  serious  mistakes  made  in  all 
of  the  above  points  and  is  confident  that  it  will  pay  to 
recognize  existing  conditions.  The  only  way  to 


FIG.    48. 

decrease  the  chance  of  errors  in  receiving  a  furnace 
report  of  analysis  is  for  the  founder  to  have  all  such 
reports  checked  after  the  iron  is  received  into  his  yard. 
To  do  this  he  should  take  two  or  three  pieces  of  pig 
iron  from  each  end,  and  two  or  three  from  the  middle 
of  every  car  of  iron  received,  or  from  the  ends  of  piles 
after  it  is  taken  from  the  car  as  described  on  page  140. 
These  pieces  of  pig  should  be  about  one-quarter  the 
length  of  a  whole  pig  and  drilled  after  one  or  the  other 
of  the  plans  seen  at  A,  B,  and  C  in  Fig.  48.  In  drill- 
ing these  samples  the  iitmost  care  should  be  taken  to 
prevent  sand  or  scale  from  the  pigs  getting  mixed 


196  METALLURGY    OF    CAST    IRON. 

with  the  drillings.  To  prevent  this  the  pigs  should  be 
thoroughly  cleaned  with  a  wire  brush  before  being 
taken  to  the  drill  press,  where  they  should  be  drilled 
with  a  flat  drill,  as  a  twist  drill  gives  a  large  variation 
in  the  size  of  borings  according  as  the  hardness  of  the 
iron  varies.  Some  drill  six  to  ten  holes  to  obtain 
samples  as  at  A,  others  drill  three  holes  as  at  B,  while 
others  drill  but  one  hole  in  the  center  as  at  C.  Where 
it  is  desired  to  obtain  the  best  possible  average  of  the 
composition  of  a  piece  of  pig  in  securing  drillings,  the 
plan  seen  at  A  is  followed.  It  may  be  said  that,  as  a 
rule,  the  majority  of  samples  are  taken  as  at  C,  unless 
analyses  of  the  carbons  are  required,  when  it  is  very 
essential  to  follow  the  plan  at  A  or  B.  In  drilling  as 
at  A  or  B  the  material  from  each  hole  should  be  kept 
separate,  and  after  the  drilling  is  completed  the  same 
weight  of  drillings  from  each  hole  should  be  taken, 
and  the  whole  mixed  together  as  thoroughly  as  pos- 
sible to  obtain  an  average  of  the  composition  of  the 
pig.  For  each  analysis  about  a  large  teaspoonful  of 
drillings  is  ample,  and  such  are  best  passed  through  a 
20-  or  4o-mesh  sieve  before  being  used.  To  do  this  it 
may  often  be  necessary  to  pulverize  the  drillings  in  an 
iron  mortar.  It  is  very  important  to  properly  sample 
a  car  or  pile  of  iron  and  take  proper  precaution  in  ob- 
taining a  clean  and  thoroughly  mixed  sample  of  drill- 
ings, where  one  wishes  an  accurate  analysis  to  show 
the  average  composition  of  a  car  or  pile  of  pig  iron. 

The  small  foundry  finds  this  method,  necessary  to 
check  furnace  reports  of  analyses,  objectionable.  This 
is  on  account  of  such  founders  not  being  in  a  position 
to  support  a  laboratory.  However,  many  small  shops 
would  find  that  it  would  pay  them,  in  the  end,  to 


PURCHASE    AND    SAMPLING    OF    PIG    IRON.  197 

send  samples  of  drillings  of  every  car  or  pile  of  iron 
by  mail  to  other  localities  where  a  chemist  could  be 
employed.  Unless  such  shops  are  doing  work  of  a  char- 
acter requiring  delicacy  in  making  mixtures,  analyses 
of  the  silicon  and  sulphur  are  all  that  they  may  require, 
of  their  pig  metal,  and  these  can  be  obtained  for  about 
one  dollar  for  each  analysis.  This  is  a  small  sum  com- 
pared to  the  assurance  it  affords  such  founders  of 
correcting  possible  errors  in  furnace  analysis  reports. 
Many  small  founders  are  now  beginning  to  recognize 
this  and  some  are  following  the  above  plan  and  find 
that  it  pays  them  well.  In  cases  where  a  small  firm 
could  give  a  chemist  other  employment  they  could 
install  a  laboratory  at  their  own  works  for  one  hundred 
to  one  hundred  and  fifty  dollars,  and  then  be  in  a  posi- 
tion not  only  to  make  analyses  of  their  own  irons  but 
also  those  of  what  fuels,  blackings,  and  sand  they  use, 
when  found  advisable. 

Another  evil  of  past  practices  has  lain  in  the  founder 
relying  upon  the  furnaceman  to  advise  him  of  the  char- 
acter of  iron  he  should  use.  This  is  wrong.  It  is  not 
a  furnaceman 's  business  to  be  responsible  for  the  char- 
acter of  iron  the  founder  should  use,  as  his  experience 
does  not  rightly  afford  him  such  knowledge.  All  foun- 
ders should  know  their  own  needs  and  be  able  to  order 
their  irons  intelligently.  The  first  two  editions  of 
this  work  have  achieved  much  in  influencing  founders 
to  do  this.  A  study  of  this  work  should  cause  the 
moulder  or  founder  who  may  now  look  upon  chemistry 
as  something  beyond  his  comprehension,  to  talk  as 
intelligently  and  fluently  about  silicon,  sulphur,  man- 
ganese, phosphorus,  and  the  carbons,  etc.,  in  iron,  as 
he  now  can  about  moulding  sand,  ramming,  venting, 


198  METALLURGY    OF    CAST    IRON. 

gating,  pouring,  etc.  The  grand  point  about  all  this 
is  the  practicability  of  its  achievement  by  any  ordinary 
mind  that  will  make  any  effort  to  master  this  new 
science  of  founding. 

A  description  of  the  methods  followed  at  our  foundry 
in  Sharpsville,  Pa.,  for  delivering  pig  iron  to  the 
cupola  and  keeping  a  record  of  our  heats,  etc.,  may 
serve  many  well  in  giving  them  ideas  to  form  plans  for 
such  work.  Our  pig  iron,  in  being  loaded  from  cars 
or  iron  piles  in  the  yard,  is  placed  on  buggies  and  then 
pushed  to  the  elevator  by  a  locomotive  or  hand  power, 
after  which  it  is  carried  to  the  cupola  stage  and  stored 
in  piles  after  the  plan  described  on  pages  141  and  142. 
A  record  of  the  silicon,  sulphur,  etc.,  contents  of  each 
pile  is  kept  by  the  cupola  tender,  so  that  he  knows  just 
what  iron  to  charge.  We  make  a  specialty  of  castings 
that  now  require  heats  ranging  from  seventy  to  one 
hundred  tons  weight.  Our  castings  are  of  such  a 
character  as  to  exact  certain  physical  qualities.  To 
know  that  they  are  right  in  our  castings  before  leaving 
our  shop,  we  have  analyses  of  the  silicon  and  sulphur, 
and  occasionally  of  the  other  metalloids  made  for 
every  heat ;  and  when  first  starting  to  make  these  anal- 
yses we  also  conducted  physical  tests.  A  plan  for 
obtaining  both  combined  is  shown  by  Tables  28  and  29. 
We  largely  dispense  now  with  the  physical  test,  owing 
to  our  experience  being  such  as  to  enable  us  to  judge  of 
the  physical  properties  by  reason  of  chemical  analysis 
and  an  examination  of  the  castings.  The  tests  given  in 
Tables  28  and  29  were  obtained  from  four  round  test  bars 
cast  on  end  at  about  equal  divisions  of  the  heat.  The 
mixture  for  the  heat  here  recorded  was  all  pig  iron,  ex- 
cepting about  5  per  cent,  shop  scrap,  the  pig  ranging 


PURCHASE    AND    SAMPLING    OF    PIG    IRON. 


I99 


from  1.30  to  2.00  per  cent,  of  silicon  and  from  .020  to 
.040  in  sulphur.  We  have  an  arrangement  for  our  office 
in  which  a  record  of  the  chemical  and  physical  qualities 
obtained  in  our  castings  can  be  recorded.  This  enables 
us  to  work  intelligently  when  wishing  to  refer  to  past 
results  or  experiences  in  repeating  old  or  making  new 
mixtures  of  iron.  These  records  are  also  kept  in  such  a 
manner  as  to  show  the  loss  in  silicon  and  increase  in 
sulphur,  etc. ,  in  our  heats,  something  which  is  very  es- 
sential to  be  understood,  and  is  treated  in  Chapter  XLV. 

TABLE  28. — PHYSICAL  TESTS  OF    "HEAT"    TAKEN    SEPTEMBER  14,    1896. 


jj 

d 

d 

.2 
2^ 

j 

g 

o 

A« 

1*1 

"3 

I 

i§« 

. 

SJ 

fl"^« 

r 

£ 
E 

3 

s 

H     • 

3 

o 

rt^ 
5 

£2*5 
9 

• 

2/8" 

.135" 

.140" 

1,955 

864" 

1-143" 

1,907 

2 

2K" 

.130" 

.110" 

I>625 

6  64" 

1.136" 

1,604 

3 

!#" 

.128" 

.120" 

1,520 

5-64" 

1.130" 

1515 

4 

2K" 

.124" 

.150- 

1,495 

4-64" 

1.142" 

1,459 

REMARKS. 


The  four  test  bars  showed  a  perfect,  solid  fracture.    The  strongest  test 
bar  was  the  last  cast  and  the  weakest  bar  at  the  second  pouring. 

[Signature  of  Tester.]  THOS.  D.  WEST. 

TABLE  29. — CHEMICAL   ANALYSIS   OF   STRONGEST   TEST   BAR. 


Silicon. 

Sulphur. 

Combined 
Carbon. 

Graphitic 
Carbon. 

Phosphorus. 

Manganese. 

1.20 

.079 

.094 

2.67 

.089 

0.40 

CHEMICAL   ANALYSIS    OF   WEAKEST   TEST    BAR. 


Silicon. 

Sulphur. 

Combined 
Carbon. 

Graphitic^ 
Carbon. 

Phosphorus. 

Manganese. 

2-15 

.060 

•79 

2-75 

.091 

•37 

[Signature  of  Chemist.]       D.  K.  SMITH. 


200  METALLURGY    OF    CAST    IRON. 

In  purchasing  pig  irons  for  any  new  class  of  work, 

or  such  as  founders  are  inexperienced  with  and  that 
others  may  be  making,  it  is  often  a  good  plan  to  find 
out  and  deal  with  the  furnace  which  can  show  dealings 
with  founders  making  the  same  class  of  work  which 
they  desire  to  manufacture  if  they  can.  This  starts  a 
founder,  in  making  a  new  class  of  work,  to  use  brands 
of  iron  that  have  been  tested  and  found  suitable  for 
the  class  of  work  he  desires  to  produce,  and  may  be 
the  means  of  preventing  some  experimenting  and  loss 
of  capital.  IT  WAS  ADVANCED  IN  THE  FOUNDRY,  Nov., 
1901,  that  buyers  of  foundry  pig  iron  should  consider 
the  fracture  of  pig  in  being  open  or  close  grained  in 
connection  with  specified  analyses.  How  practical 
this  proposition  is  will  be  found  by  reference  to  page 
179.  Methods  for  computing  averages  of  silicon, 
sulphur,  etc.,  that  exist  in  different  furnace  casts  or 
piles  of  iron,  in  making  mixtures  of  any  special  brands 
or  different  grades,  are  given  in  Chapter  XXXVI., 
Tables  39  to  42,  pages  256  and  257.  The  net  weight 
of  sand  and  chill  cast  pig  iron  per  ton  of  2,268  Ibs.  and 
2,240  Ibs.  respectively  is  given  in  the  first  two  tables 
at  the  close  of  this  work. 


PART  II. 


CHAPTER  XXVIII. 

THE  METALLIC  AND  NON-METALLIC 
ELEMENTS  OF  CAST  IRON. 

Having  described  processes  followed  in  making  cast 
iron  and  qualities  affecting  its  character,  etc. ,  up  to  the 
time  it  arrives  in  pig  form  at  foundries,  ready  for  re- 
melting  to  make  castings,  as  seen  in  Chapters  I.  to 
XXVII.,  we  will  now  treat  of  qualities  which  can 
affect  cast  iron  when  in  the  hands  of  founders,  and 
of  information  which  they  should  possess  in  order  to 
make  mixtures  best  suited  for  different  kinds  of  gray 
and  chilled  castings;  also  on  subjects  pertaining  to 
testing,  etc. 

While  the  effects  of  silicon  and  sulphur,  manganese, 
phosphorus,  and  carbon  have  been  referred  to  some- 
what in  the  preceding  chapters,  it  has  only  chiefly 
been  done  in  a  manner  incidental  to  the  manufacture 
of  cast  iron.  It  is  when  pig  or  cast  iron  is  in  the 
hands  of  founders  that  its  peculiarities  or  .character- 
istics are  best  displayed.  For  this  reason,  the  second 
part  of  this  work  will  be  found  the  more  important  in 
imparting  information  on  cast  iron  to  those  em- 
ployed in  the  manufacture  of  castings  or  interested 
in  their  use.  In  taking  up  this  second  part  of  the 
work,  it  will  be  well  to  first  treat  of  the  metallic  and 
non-  metallic  elements  of  cast  iron. 

An  element  is  a  substance  composed  of  only  one 


ELEMENTS    OF    CAST    IRON.  203 

kind  of  atoms.  An  atom  is  the  smallest  sub-division 
of  matter  which  cannot  be  divided.  Every  atom  is 
exactly  like  every  other  atom  of  the  same  kind  and  is, 
as  a  rule,  incapable  of  independent  existence.  Atoms 
unite  to  form  molecules,  which  are  the  smallest  parti- 
cles of  matter  capable  of  independent  existence  to 
retain  the  properties  of  a  mass,  and  which  is  any  form 
of  matter  appreciable  to  the  senses.  Molecules  can  be 
formed  of  one  or  different  kinds  of  atoms.  Where 
molecules  are  formed  of  different  kinds  of  atoms,  the 
mass  is  called  a  compound.  There  are  now  about 
seventy  different  kinds  of  atoms  or  elements,  among 
which  are  classed  carbon,  iron,  manganese,  phos- 
phorus, silicon,  and  sulphur.  Table  130,  at  the  close 
of  this  work,  gives  the  chemical  and  atomic  weights  of 
various  elements. 

One  method  of  distinguishing  the  metallic  elements 
or  atoms  from  the  non-metallic  ones  is  as  follows :  Solu- 
tions of  compounds  are  sometimes  decomposed  by  an 
electric  current.  That  element  which  will  go  to  the 
positive  pole  is  said  to  be  the  electro-negative  or  non- 
metallic,  while  that  element  which  goes  to  the  negative 
pole  is  said  to  be  electro-positive  or  metallic.  This  divi- 
sion of  elements  among  iron  workers  is  more  generally 
understood  in  being  classed  as  metals  and  metalloids, 
the  latter  being  limited  to  inflammable  non-metallic 
elements,  and  which  as  a  rule  are  lighter,  bulk  for 
bulk,  than  metals.  With  this  conception  of  the  ele- 
ments, we  can  consider  iron,  manganese,  and  silicon 
as  being  metals,  while  the  carbon,  sulphur  and  phos- 
phorus would  be  classed  as  metalloids.  While  this 
classification  may  be  accepted,  it  is  for  convenience, 
with  founders  especially,  considered  that  the  term 


204  METALLURGY    OF    CAST    IRON. 

metalloids  shall  cover  every  element  in  cast  iron  ex- 
cepting the  iron.  This  implies  that  one  or  all  of  the 
elements  —  carbon,  silicon,  sulphur,  manganese,  and 
phosphorus  —  are  classified  as  metalloids,  but  it  is  to 
be  remembered  that  this  is  incorrect  in  regard  to  man- 
ganese. To  have  a  clear  understanding  of  the  influence 
of  these  metalloids  in  affecting  the  character  of  iron  or 
castings,  a  study  of  the  following  chapters  is  necessary. 


CHAPTER  XXIX. 

CHEMICAL   AND    PHYSICAL   PROPERTIES 
OF  CAST  IRON. 

Without  chemistry  we  could  not  define  elements 
causing  physical  effects  or  be  able  to  scientifically  and 
intelligently  direct  mixtures.  The  physical  test  tells 
us  what  is  obtained.  The  chemical  test  tells  us  the 
metalloids  we  must  use  to  effect  results,  and-  each 
property  is  essential  to  an  attainment  of  the  desired 
end.  The  first  to  be  noted  is  carbon,  as  its  influence 
in  the  form  of  graphite  or  combined  carbon  is  the 
greatest  in  determining  the  character  or  ' '  grade  ' '  of 
cast  iron. 

The  amount  of  carbon  which  iron  will  absorb  depends 
upon  the  working  conditions  of  a  furnace  and  the 
amount  of  silicon,  phosphorus  and  manganese  taken  up 
by  the  iron.  Much  silicon  reduces  the  power  of  iron 
to  absorb  carbon.  The  greater  the  percentage  of 
manganese  the  more  carbon  can  iron  absorb,  as  is 
shown  by  ' '  Spiegel ' '  iron,  which  contains  carbon  as 
high  as  six  per  cent.  When  iron  is  below  .75  in  man- 
ganese, about  3.50  of  carbon  is  all  it  contains,  although 
it  may  possess  as  much  as  4.50  per  cent,  of  carbon  in 
rare  cases.  It  is  claimed  that  chromium,  when  sub- 
stituted for  manganese,  will  cause  iron  to  absorb  carbon 
as  high  as  1 2  per  cent.  The  carbon  in  iron  is  ob- 


206  METALLURGY    OF    CAST    IRON. 

tained  from  the  fuel  used  in  smelting.  The  more  car- 
bon iron  contains,  the  greater  influence  silicon,  etc., 
can  have  in  affecting  or  changing  the  ' '  grade  ' '  of  iron. 
The  carbon  in  gray  iron  is  mostly  in  the  form  of 
graphite,  and  the  iron  may  contain  as  much  as  three 
to  four  per  cent,  of  it.  Hard  or  "  white  iron  "  contains 
carbon  in  a  different  state  from  "  gray  iron. ' '  In  white 
iron  it  is  chiefly  combined  carbon,  in  which  form  it 
hardens  the  iron.  The  graphitic  carbon  in  gray  iron 
can  have  a  large  percentage  made  combined  carbon,  to 
harden  iron,  by  casting  it  on  a  chill  or  suddenly  cool 
ing  it.  By  this  action  the  carbon,  which  in  melted 
iron  is  in  the  state  of  combination,  does  not  have  time 
to  separate  in  the  form  of  graphite. 

Combined  carbon  is  ascertained  in  true  chemical  ex- 
hibits of  pig  metal  by  the  fracture  being  small  grained, 
of  a  close,  compact  nature,  and  tending  to  a  light  gray 
color  in  Nos.  i  to  5,  and  in  the  higher  numbers  to  a 
white  color.  The  higher  its  percentage  in  combined 
carbon,  the  greater  the  approach  to  white  iron.  The 
faster  the  iron  cools  and  the  more  combined  carbon  it 
contains,  the  finer  the  crystals  or  grain.  The  lowest 
combined  carbon  is  found  in  castings  having  from 
three  to  four  per  cent,  of  silicon,  and  low  in  sulphur. 

Graphitic  carbon  can  be  told  in  iron  by  the  fracture 
being  large  grained  and  its  crystals  of  a  deep,  brilliant 
color,  from  which  flakes  of  graphite  can  often  be  ex- 
tracted by  hand  or  brushed  out.  A  large  percentage 
of  graphite  in  iron  will  make  it  very  soft,  unless  re- 
tarded by  the  presence  of  some  hardening  substance, 
like  manganese.  The  more  slowly  a  casting  cools,  the 
more  graphite  in  the  iron,  and  the  larger  the  grain. 
For  characteristic  determinations  of  combined  carbon 
in  a  fluid  state,  see  Chapter  LX. 


OF  TH 

UNIVER. 

CHEMICAL    AND    PHYSICAL    PROPERTIES,   ETC.\      207     OF 

^LJFOf 

Total  carbon  is  that  composing  the  combined  and 
graphitic  carbon  united.  Where  the  total  is  known 
and  only  the  combined  is  stated,  the  balance  necessary 
to  make  the  total  would  be  the  graphite,  and  the 
reverse  where  the  graphite  is  only  known.* 

Woolwich's  experiments  have  proved  that  variations 
in  the  percentage  of  combined  carbon  are  more  effect- 
ive in  changing  the  grade  of  an  iron  than  equal  varia- 
tions in  graphite  carbon.  A  slight  increase  in  graph- 
ite, with  the  combined  carbon  remaining  constant, 
creates  very  little  effect  in  changing  the  grade  to  make 
a  softer  iron,  but  if  a  like  change  should  be  made  in 
the  combined  carbon,  having  the  graphite  remain  con- 
stant, the  ratio  would  be  greatly  changed  or  the 
' '  grade  ' '  of  the  iron  would  be  very  much  altered. 

Silicon's  chief  office  is  to  soften  iron  and  aid  the 
founder  to  regulate  or  cheapen  his  mixture.  This 
was  first  suggested  by  Dr.  Percy  in  the  year  1850, 
but  it  awaited  experiments  in  1885  by  Mr.  Charles 
Wood,  a  founder  of  Middlesbrough,  assisted  by  Mr. 
John  C.  Stead,  the  expert  chemist,  both  of  England,  to 
first  practically  demonstrate  the  value  and  utility 
of  silicon  as  a  softener  and  its  application  to  found- 
ing, a  work  which,  it  should  be  said,  had  its  founda- 
tion laid  in  experiments  conducted  by  Prof.  Thomas 
Turner,  at  Mason  College,  Birmingham,  Eng.,  the 
same  being  presented  a  few  months  later  at  the 
Glasgow  meeting  of  the  Iron  and  Steel  Institute.  The 
extensive  publication  of  this  paper  is  really  responsible 
for  the  universal  adoption  of  silicon  as  a  softener 
in  making  mixtures  of  iron.  The  next  to  take  up 

*For  further  information  regarding  the  "total  carbon,"  see 
Chapter  XXXIII. 


208  METALLURGY    OF    CAST    IRON. 

this  work  was  M.  Fred  Gautier,  of  Paris,  who,  at  the 
next  spring  meeting  of  the  above  association,  pre- 
sented a  paper  on  silicon  in  foundry  iron.  These  two 
papers  started  many  others  experimenting,  among  the 
most  prominent  being  Mr.  W.  J.  Keep,  of  Detroit, 
Mich.,  and  the  author. 

Not  only  is  silicon  a  softener  of  iron  and  a  great  ele- 
ment in  cheapening  the  mixture  by  permitting  a  large 
percentage  of  scrap  or  cheap  iron  being  mixed  with 
high-silicon  iron,  but  it  is  also  an  element  of  value  in 
increasing  the  fluidity  of  metal.  Silicon  possesses  a 
property  which,  in  a  degree,  reduces  the  percentage 
of  total  carbon  which  iron  may  take  up,  and  which  also 
can  exceed  in  its  percentage  any  other  element  in  iron. 
It  has  found  such  a  favor  in  the  estimation  of  some 
as  to  make  them  unregardful  of  any  other  element  in 
iron,  a  practice  which  is  decidedly  wrong,  from  the 
fact  that  one  part  of  sulphur  can  often  neutralize  the 
effect  of  ten  to  fifteen  parts  of  silicon,  and  hence  for 
this  reason  it  is  as  essential  that  the  founder  should 
be  as  watchful  of  sulphur  as  silicon,  and  the  same 
may  be  said  of  the  total  carbon,  phosphorus,  and 
manganese,  as  all  should  be  considered  in  making  mix- 
tures ;  but  the  silicon  and  sulphur  should  be  considered 
the  bases  for  changing  the  grade  or  character  of  iron, 
as  seen  by  Chapter  XVII. 

The  author's  experience  and  study  of  silicon  in  its 
effect  upon  mixtures  lead  him  to  affirm  that  while  it 
can  achieve  much  good,  it  can  also  do  great  injury.  It 
is  an  element  which  should  only  be  used  with  a  knowl- 
edge of  the  effect  any  percentage  can  produce,  just  as 
a  physician  can  administer  a  poisonous  drug  to  obtain 
beneficial  results.  Silicon  is  a  very  good  thing,  so  is 


CHEMICAL    AND    PHYSICAL    PROPERTIES,    ETC.          2OQ 

good  whiskey,  but  either,  if  not  carefully  used,  can 
cause  more  evil  than  good.  For  this  reason,  guesswork 
in  judging  the  amount  of  silicon  an  iron  contains  is  not 
to  be  commended.  Only  by  a  knowledge  of  its  chem- 
ical analysis  can  constant,  uniform  or  desired  results 
in  applying  silicon  to  mixtures  be  best  maintained.  I 
have  found  that  silicon  had  a  softening  effect  up  to 
about  4.00  per  cent.,  or  where  it  was  possible  to  have 
castings  jolted  in  safety  over  a  pavement  or  rail  track 
in  transit  for  delivery. 

This  is  as  far  as  the  founder  ought  to  go  in  vising 
such  "  poison  "  to  strength.  After  the  carbon  has  be- 
come graphitic  all  it  will,  any  further  addition  of  sili- 
con only  closes  the  grain  and  makes  the  casting  "soft 
rotten,"  or  brittle.  If,  by  still  further  addition  we 
would  exceed  four  per  cent,  of  silicon — which  is  a  per- 
centage no  ordinary  iron  mixtures  or  casting  requir- 
ing any  strength  at  all  should  contain — we  may  then 
harden  the  iron  to  a  slight  degree.  A  mixture  having 
3.75  per  cent,  of  silicon  is  as  high  in  that  element  as 
it  is  practical  to  use,  if  we  expect  general  castings  to 
hold  together,  unless  the  sulphur  or  manganese  is  very 
high  to  harden  the  iron.  It  is  not  desirable  to  have 
ferro-silicon  iron  in  castings.  Very  few  general 
castings,  excepting  those  for  electrical  purposes,  re- 
quire over  three  per  cent,  of  silicon  in  their  composi- 
tion, if  the  sulphur  or  manganese  is  right,  and  the  lower 
the  silicon  can  practically  be  kept  in  most  castings  the 
better  the  results  to  be  expected  from  its  use. 

In  Russia,  they  have  made  light  castings,  as  was 
shown  in  the  exhibit  at  the  World's  Fair,  1893,  with 
the  silicon  as  low  as  .55,  a  little  over  one-half  of  one 
per  cent.,  but  in  order  to  achieve  this,  we  find  the 


210  METALLURGY    OF    CAST    IRON. 

sulphur  did  not  exceed  .022.  This  is  a  good  ex- 
ample in  illustration  of  the  effect  of  sulphur  in  harden- 
ing iron,  for  had  the  sulphur  been  .07,  as  is  generally 
the  case  as  an  average  for  light  castings  in  America, 
with  the  silicon  only  .55,  such  castings  would  be  so 
hard  or  "white,"  that  they  would  never  hold  together 
long  enough  for  one  to  handle  them.  The  low  sulphur 
in  the  Russian  castings  would  lead  us  to  say  that  they 
were  made  from  cold  blast  charcoal  iron.* 

Silicon  can  be  absorbed  by  iron  to  as  high  as  20  per 
cent.,  and  from  3  to  4  per  cent,  of  silicon  in  mixture 
will  generally  change  all  the  carbon  found  in  ordinary 
irons  to  graphite  that  it  is  possible  to  change.  The 
percentage  it  will  require  to  do  this  is  dependent 
upon  the  percentage  of  the  other  constituents  present 
in  the  mixture.  Silicon  ranges  from  i  to  5  per  cent, 
in  Foundry  iron,  in  standard  Bessemer  iron  from  i  to 
2^/2.  per  cent.,  and  in  ferro-silicon  pig  iron  from  5  to  14 
per  cent.  In  making  mixtures  of  iron  with  pig  con- 
taining 4  to  6  per  cent,  of  silicon  there  is  far  less  risk 
of  over-  dosing  a  mixture  than  with  pig  containing 
from  8  to  14  per  cent,  of  silicon,  for  although  we  may 
figure  out  to  a  nicety  just  the  percentage  pig  may  con- 
tain and  direct  how  many  pounds  should  be  charged, 
it  cannot  but  be  seen  that  with  the  higher  percentage 
of  silicon  pig  the  least  error  in  weighing  it,  etc. ,  could 
be  very  disastrous  in  results.  In  cases  where  a  found- 
er has  a  cheap  class  of  work  and  desires  to  use  all  the 
scrap,  burnt  or  hard  iron  possible,  he  may  often  use 

*  The  Russian  analysis  was  obtained  by  Mr.  H.  L.  Hollis,  of  Chi- 
cago, and  presented  in  a  table  with  other  analyses  of  American 
castings  in  a  paper  read  before  the  Western  Foundry  men's  Asso- 
ciation, May,  1894. 


CHEMICAL    AND    PHYSICAL    PROPERTIES,    ETC.          211 

ferro-silicon  pig  very  economically,  or  where  a  founder 
is  running  on  a  specialty  of  any  kind  that  does  not  re* 
quire  different  mixtures  out  of  the  same  heat,  with 
good  judgment  and  care,  ferro-silicon  may  often  be 
well  and  profitably  applied  in  mixture.*  Four  per  cent, 
of  silicon  pig  can  often  carry  80  per  cent,  of  ordinary 
scrap  to  make  soft,  machinable  castings  in  work  not 
under  one  inch  in  thickness. 

Silicon  in  the  pig  has  a  silver  cast,  and,  with  some 
grades,  a  -  flaky,  frost-on-the-window  look.  It  has 
practically  no  grain  and  when  broken  has  a  fracture 
somewhat  like  glass.  For  its  appearance  in  a  liquid 
state,  see  Chapter  LX, 

Sulphur  in  iron  is  mainly  derived  from  the  fuel 
used  to  smelt  it  in  the  blast  furnace  and  in  remelting 
it  in  a  cupola.  It  is  the  most  uncontrollable,  injurious 
element  the  furnaceman  or  founder  has  to  contend 
with.  There  are,  however,  three  qualities  sometimes 
commendable  in  it:  one  is  its  influence  in  increasing 
the  fusibility  of  iron,  and  another  its  strength,  as 
shown  in  Chapter  XXX.,  and  the  third  its  tendency 
to  harden  or  chill  iron  by  reason  of  its  promoting 
combined  carbon,  which  is  often  better  obtained  with 
low  silicon  or  high  manganese,  since  with  these  we 
have  less  injury  from  unyielding  contraction  strains. 
With  the  exception  of  the  three  qualities  mentioned 
above,  the  effects  of  sulphur  are  greatly  for  evil,  mak- 
ing light  castings  hard  and  molten  iron  sluggish,  and 
giving  rise  to  "  blow  holes  "  in  iron  solidifying  rapid- 
ly. It  is  for  these  various  reasons  that  charcoal  iron, 
on  account  of  its  being  low  in  sulphur,  has  been  found 
superior  to  coke  or  anthracite  iron  for  many  kinds  of 
castings. 

*  Some  keep  a  stock  of  ferro-silicon  on  hand  to  regulate  mixtures  in  the  ab- 
sence of  their  3.00  to  4.00  per  cent,  silicon  irons,  as  a  little  goes  a  long  ways  and 
often  prevents  shutting  down  for  the  want  of  regular  irons. 


212  METALLURGY  OF  CAST  IRON. 

With  charcoal  iron  castings  we  can  have  low  silicon 
without  much  sulphur,  whereas  with  coke  and  anthra- 
cite iron  castings,  if  we  have  low  silicon,  we  may 
generally  expect  high  sulphur.  Charcoal  pig  metal 
being  the  most  free  from  sulphur  and  impurities,  the 
softest  strong  castings  are  obtained  from  it,  especially 
when  melted  in  an  air  furnace.  Sulphur  is  very  de- 
ceptive in  pig  metal.  It  can  lurk  in  hiding  so  as  to  be 
present  to  a  much  greater  degree  than  the  eye  of  an 
expert  can  suspect.  For  this  reason  chemical  analysis 
is  very  essential  in  order  to  ferret  it  out.  Sulphur  can 
cause  iron  to  be  red  short,  as  well  as  cold  short. 

Two  points  of  sulphur  are  more  effective  in  changing 
the  character  of  iron  than  ten  to  fifteen  points  of 
any  other  constituent  which  iron  possesses.  Its  influ- 
ence in  so  greatly  changing  the  character  of  iron  is  due 
to  its  ability  to  radically  increase  the  percentage  of 
combined  carbon  in  iron.  The  alteration  that  a  few 
points  in  sulphur  can  effect  in  the  *  *  grade  ' '  of  iron  is 
often  surprising,  and  for  this  reason  founders  should 
be  most  watchful  of  sulphur.  The  amount  of  sulphur 
in  pig  metal  generally  ranges  from  .01  for  No.  i  iron 
up  to  .10  for  "white  iron."  For  No.  i  pig  metal  it 
rarely  exceeds  0.03;  Nos.  3  to  4,  0.05,  and  for  white 
pig  iron  o.io.  Sulphur  in  iron  can  cause  excessive 
shrinkage  as  well  as  contraction,  the  former  often  be- 
ing the  cause  for  shrink  holes  and  the  latter  for  cracks 
in  castings.* 

Manganese,  when  increasing  the  combined  carbon, 
will  deepen  the  chill  and  cause  greater  shrinkage  and 
contraction,  and  to  a  limit  greatly  strengthens  iron. 

*For  an  article  on  the  effects  of  sulphur  in  strengthening  iron, 
see  Chapter  XLIII. 


CHEMICAL    AND    PHYSICAL    PROPERTIES,    ETC.  213 

Manganese  is  readily  absorbed  by  slag  and  can  be  car- 
ried off  as  oxide  of  manganese  during  a  heat,  and  in 
cupola  work  will  greatly  assist  in  carrying  off  sulphur 
by  means  of  ' '  slagging  out. ' '  Manganese  ranges  from 
a  trace  up  to  3  per  cent,  in  pig  iron.  The  general  run 
of  good  gray  pig  iron  averages  about  .50;  over  i.oo 
per  cent,  it  would,  in  light  work,  unless  proportionately 
higher  than  2. 50  per  cent,  in  silicon,  be  injurious  in 
causing  hard  castings,  and  it  is  seldom  in  massive 
work  requiring  strength  that  it  would  be  beneficial  for 
manganese  to  exceed  2.00  per  cent.  Manganese  can 
counteract  the  red  shortness  caused  by  sulphur  and 
greatly  neutralize  the  effect  of  sulphur  to  harden  iron 
mixtures.  It  can  be  used  as  a  physic  to  purify  liquid 
iron.  If  the  iron  is  high  in  sulphur  it  will  be  beneficial 
in  expelling  it  and  thereby  lessen  the  chances  of  ' '  blow 
holes  ' '  by  expelling  oxides  or  occluded  gases. 

A  very  peculiar  property  that  has  been  noticed  in  pig 
iron  containing  2  to  3  per  cent,  of  manganese  is  that 
while  it  may  look  open-grained,  like  a  good  No.  i  soft 
iron,  it  has  been  found  so  hard  that  it  could  only  with 
difficulty  be  drilled.  Manganese  gives  fluidity  and 
life  to  molten  metal,  causing  it  to  occupy  greater  time 
in  solidifying.  In  pig  metal,  as  well  as  in  castings,  it 
can  cause  the  crystals  to  be  coarse  grained,  though 
the  iron  can  be  hard,  as  above  stated. 

Manganese  is  often  found  as  high  as  2.50  per  cent. 
in  foundry  pig  metal  and  still  make  good  machinable 
castings.  This  quality  is  partly  due  to  the  great 
activity  which  manganese  has  in  expelling  sulphur  in 
remelting  iron.  Sulphur  is  the  element  of  greatest 
power  in  causing  hardness  in  castings;  but,  on  the 
other  hand,  sulphur  can  often  be  so  eliminated  by  man- 


214  METALLURGY    OF    CAST    IRON. 

ganese;  that  for  this  reason  manganese  can  often  be 
high  and  still  soft  castings  be  obtained.  The  better  a 
cupola  is  fluxed  and  the  higher  its  temperature,  the 
more  the  manganese  will  be  decreased.  In  making 
or  remelting  iron,  manganese  is  affected  in  a  man- 
ner somewhat  similar  to  silicon.  A  hot  working  fur- 
nace will  send  the  manganese  into  the  pig,  where  a 
cold  working  furnace  will  send  it  into  the  slag,  as  it 
requires  high  heat  to  make  manganese  combine  with 
the  iron,  when  making  it. 

A  phenomenon  peculiar  to  manganese  is  to  be  cited 
in  the  opposite  results  which  manganese  exerts  when 
in  the  pig,  in  process  of  being  melted,  and  when  it  is 
added  as  ferro-manganese  to  soften  hard  grades  of 
molten  metal,  as  is  practiced  by  some  founders.  The 
author  cannot  explain  the  phenomenon  better  than  by 
here  inserting  comments  by  Mr.  Alexander  E.  Outer- 
bridge,  Jr.,  in  a  paper  presented  by  him  before  the 
Franklin  Institute,  February  2,  1888: 

A  remarkable  effect  is  produced  upon  the  character  of  liard  iron 
by  adding  to  the  molten  metal,  a  moment  before  pouring  it  into 
a  mould,  a  very  small  quantity  of  powdered  ferro-manganese,  say 
one  pound  of  ferro-manganese  in  600  pounds  of  iron,  and  thor- 
oughly diffusing  it  through  the  mass  by  stirring  with  an  iron 
rod.  The  result  of  several  hundred  carefully  conducted  experi- 
ments which  I  have  made  enables  me  to  say  that  the  traverse 
strength  of  the  metal  is  increased  from  thirty  to  forty  per  cent. , 
the  shrinkage  is  decreased  from  twenty  to  thirty  per  cent.,  and 
the  depth  of  the  chill  is  decreased  about  twenty-five  per  cent., 
while  nearly  one-half  of  the  combined  carbon  is  changed  into 
free  carbon ;  the  percentage  of  manganese  in  the  iron  is  not  sen- 
sibly increased  by  this  dose,  the  small  proportion  of  manganese 
which  was  added  being  found  in  the  form  of  oxide  in  the  scoria. 
The  philosophical  explanation  of  this  extraordinary  effect  is,  in 
my  opinion,  to  be  found  in  the  fact  that  the  ferro-manganese  acts 


CHEMICAL    AND    PHYSICAL    PROPERTIES,   ETC 


215 


simply  as  a  de-oxidizing  agent,  the  manganese  seizing  any  oxygen 
which  has  combined  with  the  iron,  forming  manganic  oxide, 
which,  being  lighter  than  the  molten  metal,  rises  to  the  surface 
and  floats  off  with  the  scoria.  When  a  casting  which  has  been 
artificially  softened  by  this  novel  treatment  is  re-melted,  the 
effects  of  the  ferro-manganese  disappear  and  hard  iron  results. 

In  the  experiments  conducted  by  the  author  (seen  in 
Chapter  XXXII.)  he  found  that,  in  iron  above  2.00 
silicon,  the  addition  of  manganese  to  molten  metal  had 
a  tendency  to  hold  the  carbon  more  in  a  combined 
form,  which  is  the  reverse  of  its  action  in  low  silicon 
irons,  and  partly  in  keeping  with  the  above  experience 
of  Mr.  Outerbridge. 

Phosphorus  is  the  element  which  differentiates 
"  Bessemer"  from  "Foundry"  iron,  and  generally 
ranges  from  a  trace  to  i  ^  per  cent,  in  ordinary  pig 
metal.  In  foundry  iron  it  generally  varies  from  25  to 
i. oo,  and  it  can  be  found  in  iron  as  high  as  7  per  cent. 
If  iron  exceeds  .  10  in  phosphorus  it  is  no  longer  regu- 
lar Bessemer,  and  may  be  often  classed  as  Foundry. 
To  make  this  distinction  between  Bessemer  and 
Foundry  iron  clear,  Table  30  is  presented: 

TABLE   30  —  CHEMICAL    ANALYSES   OF   FOUNDRY   AND   BESSEMER    IRONS. 


No.  I 

Foundry. 

No.  3 
Foundry. 

No.  4 
Bessemer. 

No.  7 
Bessemer. 

Phosphorus 

60 

CQ 

09 

09 

Graphitic  Carbon  

3  5° 

3.00 

3-5° 

3.  co 

Combined  Carbon        .  ... 

15 

•3° 

•35 

65 

Silicon  

3.00 

2.25 

2.OD 

1.25 

Sulphur  

.01 

.02 

.025 

.050 

Manganese 

v> 

40 

SO 

•4S 

As  can  be  seen  by  the  above  table,  excepting  phos- 
phorus, the  four  analyses  could  pass  as  Foundry  iron. 
Further  comments  on  Foundry  versus  Bessemer  will 
be  found  in  Chapter  XXII. 


2l6  METALLURGY    OF    CAST    IRON. 

Over  0.75  per  cent,  of  phosphorus  can  cause  iron  to 
be  ' '  cold  short, ' '  which  means  brittle  when  cold,  and  it 
may  harden  iron  if  used  in  excess  of  1.30  in  castings. 

By  keeping  phosphorus  down  to  between  0.20  and 
0.40,  with  silicon  from  2.50  to  2.75  and  sulphur  about 
.05,  thin  castings  can  often  be  made  so  as  to  bend 
considerably  before  breaking,  and  also  admit  of  cast 
iron  being  readily  punched  with  holes,  similarly  in  some 
degree  as  wrought  iron  would  be  affected  by 
like  •treatment.  It  has  been  contended  that  phos- 
phorus is  in  no  wise  beneficial  to  the  strength  of  an 
iron,  but  Woolwich's  experiments  would  show  that 
phosphorus  running  from  about  0.20  to  0.50  is  bene- 
ficial in  improving  the  ductile  qualities  in  physical 
tests  for  cast  iron  work.  Phosphorus  is  chiefly 
obtained  from  the  ore  and  flux.  It  retards  the  satura- 
tion of  iron  for  carbon  and  adds  fluidity  and  life  to 
metal.  It  is  the  most  weakening  element  iron  can 
possess  when  used  in  excess,  and  is  often  objectionable 
when  it  exceeds  i.oo  per  cento  in  Foundry  iron,  in 
which  it  is  best  kept  down  to  not  exceed  .80.  Neces- 
sity for  extra  fluidity,  or  life,  to  the  liquid  metal  is 
the  only  occasion  where  phosphorus  should  be  permitted 
to  exceed  .80  in  Foundry  iron. 

While  phosphorus  is  an  element  very  essential  to 
the  success  of  founding,  it  generally  needs  to  be 
guarded  as  closely  as  sulphur  or  silicon,  and  an 
intelligent  use  of  it  will  prove  that  it  can  strongly 
influence  mixtures  and  the  life  and  wear  of  castings. 
The  author  takes  pleasure  in  citing  here  some  experi- 
ences of  Mr.  James  A.  Beckett,  of  Hoosick  Falls, 
N.  Y.,  in  experimenting  in  a  practical  way  with 
phosphorus  as  an  agent  to  regulate  actual  mixtures 


CHEMICAL    AND    PHYSICAL    PROPERTIES,    ETC.  217 

used  in  a  foundry.  He  writes  the  author  that  he  has 
found  it  to  greatly  counteract  the  tendency  of  sulphur 
to  increase  combined  carbon  and  that  he  has,  upon 
several  occasions  where  high  sulphur  was  giving 
trouble  in  making  castings  hard,  by  increasing  the 
phosphorus  from  0.50  to  0.75  made  castings  soft,  that 
could  not  otherwise  be  machined.  Of  course,  he  could 
have  attained  the  same  end  by  increasing  the  silicon  or 
reducing  the  sulphur,  but  conditions  permitted  Mr. 
Beckett  to  experiment  with  phosphorus  in  order  to  ob- 
tain knowledge  as  to  its  exact  influence  when  the 
other  metalloids  were  remaining  fairly  constant.  His 
experience  in  this  line  is  of  much  value,  and  it  gives 
the  author  pleasure  to  record  them  here,  as  Mr.  Beck- 
ett is  known  to  be  a  good  manager.  Mr.  Beckett's 
experience  in  regulating  mixtures  by  phosphorus  also 
affirms  that  generally  each  tenth  of  one  per  cent,  in- 
crease of  phosphorus  will  give  about  the  same  results, 
physically,  that  an  increase  of  one-quarter  of  one  per 
cent,  silicon  will  give,  if  the  phosphorus  is  unchanged, 
until  the  total  quantity  of  phosphorus  reaches  the  limit 
of  safety,  viz.,  i.oo  per  cent.,  and  that  mixtures  in 
which  the  fluidity  is  increased  in  this  way  within  such 
limits  will  be  found  to  produce  castings  freer  from 
blow-holes  and  shrink  spots  than  if  silicon  were  entirely 
depended  upon  for  giving  fluidity.  (See  Chap.  XXXI.) 
Chromium,  as  shown  by  Thomas  Turner,*  is  not 
uncommonly  present  in  small  quantities  in  ordinary 
iron  ores.  It  has  been  found  as  high  as  .  1 2  in  samples 
of  pig  iron,  by  J.  E.  Stead. f  It  has  increased  the 
power  of  iron  to  absorb  carbon  up  to  12  per  cent. 

*Metallurgy  of  Iron,  page  205. 

flron  and  Steel  Institute  Journal,  1893,  Vol.  i,  p.  168. 


2l8  METALLURGY    OF    CAST    IRON. 

Especial  alloys  of  iron  and  chromium,  called  ferro- 
chromes,  containing  as  high  as  84  per  cent,  of  chromi- 
um, are  shown  by  Turner  to  have  been  attained.  He 
also  says  that  though  ferro-chrome  is  more  refractory 
than  ordinary  cast  iron,  and  is  very  fluid,  it  runs 
dead  and  solidifies  rapidly  and  renders  iron  hard,  white, 
and  brittle,  behaving  in  an  exactly  opposite  manner 
from  silicon  or  aluminum.  Much  more  might  be  said 
of  this  constituent,  but  as  it  has  been  found  up  to  the 
present  time  of  little  value  to  founding,  space  is 
reserved  for  more  important  elements. 

The  constituents  of  iron,  carbon,  silicon,  sulphur, 
manganese,  and  phosphorus  above  described  are  recog- 
nized as  the  chief  elements  in  controlling  the  character 
of  iron.  Aluminum,  magnesium,  sodium,  potassium 
and  calcium,  as  well  as  titanium,  copper,  and  arsenic, 
are  elements  found  in  iron.  But  of  late  years  little 
note  is  taken  of  them  by  chemists,  as  they  have  been 
regarded  as  having  practically  little  if  any  weight  in 
affecting  mixtures  or  the  character  of  commercial  iron, 
and  hence  we  have  omitted  to  discuss  their  character- 
istic qualities  to  any  length  in  this  work.  We  may 
state  that  titanium  ores  were  at  one  time  used  to  some 
extent  in  obtaining  strong  iron,  but  owing  to  the 
titanic  acid  of  titaniferous  ores  making  an  infusible 
slag  and  causing  great  trouble  in  smelting,  they  were 
seldom  if  ever  used.  However,  by  recent  improve- 
ment, as  seen  on  page  31,  such  ores  may  come  more 
into  practical  use. 

Commercially  pure  iron,  the  ideal  held  up  by  some 
works  to  be  attained,  is  not  the  element  iron  free 
from  every  contamination,  but  iron  with  about  2  per 
cent,  of  carbon  and  free  from  sulphur,  phosphorus, 


CHEMICAL    AND    PHYSICAL    PROPERTIES,   ETC.  219 

silicon,  and  manganese.  In  getting  this  iron  to  a  fluid 
condition  it  will  be  so  full  of  gas  and  run  so  sluggish 
that  the  casting,  if  obtained  at  all,  will  be  full  of  blow 
holes.  Add  silicon  to  this  iron  and  a  good  sound  cast- 
ing will  result. 

The  physical  properties  of  cast  iron  may  be  said  to  con- 
sist of  density,  tenacity,  elasticity,  strength,  toughness, 
brittleness,  and  chill.  These  may  all  differ  in  having 
characteristic  qualities  in  different  brands  or  classes 
of  iron.  The  first  of  these  elements  is  to  be  attributed 
to  what  is  called  the  ' '  grain, ' '  and  the  degree  of 
density  is  the  basis  of  grading  our  iron  by  ,  fracture 
from  No.  i  (our  most  open,  large-grained  iron)  up 
through  Nos.  2,  3,  4,  5,  6  to  10;  the  latter  two  being 
almost  as  close-grained  as  a  piece  of  glass,  and 
generally  called  "  white  iron."  A  cubic  foot  of  white 
iron  weighs  about  sixty  pounds  more  than  a  cubic 
foot  of  No.  i  iron.  "  White  iron  "  will  sink  in  a  ladle 
of  liquid  No.  i  iron,  whereas  a  piece  of  No.  i  would 
float  on  its  surface. 

Tenacity  of  cast  iron  is  that  element  which  resists  a 
pulling  apart  of  its  body  or  a  separation  of  its  mole- 
cules, as  by  a  tensile  strength  test. 

Elasticity  is  that  quality  which  permits  cast  iron  to 
stretch  or  bend  and  then  return  to  its  original  position 
or  shape  when  the  load  is  removed.  Should  the  load 
be  so  great  that  the  iron  will  not  return  to  its  original 
shape,  it  partakes  of  what  is  called  a  permanent  set, 
or  has  overreached  its  limit  of  elasticity,  a  point  which, 
when  attained  in  cast  iron,  is  very  close  to  the  break- 
ing load. 


220  METALLURGY    OF    CAST    IRON. 

Average  cast  iron,  when  sound,  "  stretches  about 
.00018,  or  one  part  in  5,555  of  its  length;  or  y%  inch 
in  57.9  feet  for  every  ton  of  tensile  strength  per  square 
inch  up  to  its  elastic  limit,  which  is  at  about  one-half 
its  break  strength.  The  extent  of  stretching,  how- 
ever, varies  much  with  the  quality  of  the  iron,  as  in 
wrought  iron. ' '  *  For  further  information  on  the 
stretching  qualities  of  cast  iron,  see  Chapter  LV., 
page  422. 

Toughness  may  be  defined  as  strength,  but  applies 
more  properly  to  that  quality  permitting  cast  iron  to 
bend  before  it  breaks,  and  in  transverse  testing,  such 
is  called  "deflection." 

Strength  of  cast  iron  is  its  ability  to  resist  transverse, 
tensile  crushing,  and  impact  blows  or  strains,  and,  in 
a  sense,  includes  tenacity,  elasticity  and  toughness. 
It  is  very  rare  that  castings  are  designed  to  resist  other 
than  transverse  or  crushing  loads.  For  this  reason 
transverse  tests  are  the  forms  of  testing  mainly  used 
to  obtain  knowledge  of  the  strength  of  cast  iron,  as  in 
securing  the  transverse  strength  of  test  bars,  we  can 
also  note  the  "deflection,"  a  quality  which  tells  us  of 
the  ductility  and  toughness  of  iron  better  than  any 
other  present  method  can.  Deflection  also  to  a  great 
degree  informs  us  of  the  softness  of  iron. 

Brittleness  is  that  quality  adverse  to  strength  and  is 
greatest  in  * '  white  "  or  "  chilled  ' '  grades  of  cast  iron, 
also  high-silicon  or  phosphorus  mixtures. 

Chill  is  that  quality  producing  a  "white"  or  crystal- 
line body  in  iron.  It  can  be  produced  by  rapid  cool- 
ing or  by  having  high  sulphur  or  low  silicon,  which 
produce,  in  the  carbon,  a  state  opposite  that  of  graph- 

*  Trautwine. 


CHEMICAL    AND    PHYSICAL    PROPERTIES,    ETC.  221 

ite.  It  is  a  physical  element  desirable  to  exist  in 
order  to  best  resist  friction  surface  wear,  and  is  chiefly 
employed  in  such  castings  as  rolls,  car  wheels  and 
crushers.  A  special  article  on  the  '  *  chill ' '  will  be 
found  in  Chapter  LVI. 

Whether  the  carbon  in  the  iron  is  combined  so  as  to 
create  a  ' '  chill, ' '  or  graphitic  to  make  soft  or  open- 
grained  iron,  largely  depends  -upon  the  time  taken  for 
the  metal  to  cool  down  to  solidification,  or  atmospheric 
temperature.  We  can  take  our  softest  irons,  highest 
in  graphitic  carbon,  and  by  pouring  when  liquid  into 
water  cause  their  carbon  to  be  largely  combined 
in  the  iron ;  and  then,  again,  we  can  take  our  hardest 
or  ' '  white  ' '  irons,  that  are  not  high  in  manganese  or 
chromium  (qualities  seldom  to  be  found  in  general  cast- 
ings), and  by  pouring  them  into  massive  castings,  like 
heavy  anvil  blocks,  cause  their  carbon  to  appear  large- 
ly of  graphite,  thus  proving  that  it  is  chiefly  a  me- 
chanical or  physical  condition,  and  not  chemical,  that 
ofttimes  can  cause  iron  to  be  soft  or  hard,  or  present 
peculiarities  in  its  physical  qualities. 

The  above  illustration  of  pouring  liquid  iron  into 
water  and  cooling  off  massive  blocks  or  castings  presents 
the  radical  extremes  of  any  physical  effects.  In  the 
rational,  common  practice  of  founding,  conditions  per- 
mit the  chemical  properties  to  have  a  control  which  com- 
pels us  to  recognize  them. as  the  chief  factor  in  dimin- 
ishing or  increasing  the  combined  carbon  or  the  hard- 
ening qualities  of  an  iron.  Nevertheless,  a  study  of 
what  physical  effects  can  produce  will  prove  to  many 
how  two  castings  can  often  be  poured  from  the  same 
ladle  of  iron  so  as  to  have  the  same  percentages  of  sili- 


222  METALLURGY    OF    CAST    IRON. 

con,  sulphur,  phosphorus  and  manganese  exist  in  the 
two  casting's,  and  still  have  the  combined  carbon  much 
higher  in  one  than  in  the  other.  (See  pages  167  and  168.) 

Concerning  the  principles  involved  in  the  strength 
of  cast  iron,  we  find  the  most  lamentable  ignorance 
exists.  Some  understand  that  there  is  such  a  thing  as 
soft  and  strong  grades  of  iron,  but  when  you  have  the 
latter  practice  ignored  and  the  first  exacted  until  the 
product  approaches  lead,  it  is  time  to  stop  and  see 
whither  we  are  drifting.  The  machine  builder,  ignor- 
ing strength  but  finding  his  castings  growing  softer, 
has  encouraged  the  foundryman  in  giving  such  soft 
castings,  until  to-day  many  of  our  machines  might  as 
well  almost  be  made  of  so  much  glass.  Such  practice 
injures  the  reputation  of  cast  iron  and  encourages  its 
being  replaced  by  steel,  etc.  It  is  not  to  disparage  the 
founder  that  the  author  writes  of  this  subject,  but  if 
possible  to  awaken  thought  and  action  toward  a  move- 
ment by  the  builders  of  machinery  for  the  exercise  of 
some  reason  and  the  attainment  of  knowledge  as  to 
where  to  draw  the  line  at  wanting  softness  at  the  sacri- 
fice of  strength.  Before  the  founder  knew  so  much 
about  silicon,  and  had  good  luck  in  mixtures,  his 
castings  would  generally  show  a  rich,  dark,  open  frac- 
ture, making  a  strong,  soft  casting,  instead  of  being 
found,  as  to-day  with  many,  in  a  close,  silvery-grained 
grade,  making  a  soft,  rotten, .  leaden  casting. 

In  using  silvery  or  silicon  pig  to  any  extent  in  mix- 
ture there  is  a  very  fine  line  to  be  drawn  in  the  use  of 
just  enough  to  attain  the  happy  medium  approaching 
strength  and  softness.  Some  would  rather  take  their 
chances  of  being  over  the  line  than  under  it,  and  many 
have  gone  over  the  line  so  far  as  to  have  castings  so 
weak  as  to  break  of  their  own  accord. 


CHAPTER  XXX. 


AFFINITY   OF   IRON  FOR   SULPHUR  AND 
ITS  STRENGTHENING  EFFECTS. 

Owing  to  a  well-known  writer  having  claimed  that 
iron  does  not  absorb  sulphur,  and  that  the  founder  has 
no  need  to  fear  its  existence  in  castings,  the  author 
presents  this  chapter  to  prove  that  the  contrary  condi- 
tion prevails.  The  following  tests  which  the  author 
made  are  such  as  can  be  repeated  by  any  one  who  may 
be  desirous  of  verifying  this  question : 

TABLE  31 — SULPHUR  TEST. 


No. 
of 
Test. 

Quality 
in 
Casting. 

Micrometer 
Measure- 
ment. 

Con- 
trac- 
tion. 

Deflec- 
tion. 

Broke 
at— 
in  Ibs. 

Chill. 

Strength 
per  sq. 
inch. 

18 
19 

Direct  bar 
Sulph.    " 

I.  TOO 

3.o89 

6-32 

7-32 

.090 
.050 

1385 
1860 

\/n 

all. 

1457 
1997 

TABLE   32  —  CHEMICAL   ANALYSIS. 


No.  of 
Test. 

Silicon. 

Sulphur. 

Manganese. 

Phosphorus. 

00  CT\ 

Iron  charged. 
Direct  bar. 
Sulph.  bar. 

.98 
•77 
.86 

.015 
.079 

•175 

•30 
•31 
•37 

.092 
.097 
•097 

Test  bar  No.  18  is  one  of  four  which  were  poured 
with  iron  direct  from  the  cupola,  with  the  ladle  hold- 
ing about  100  pounds  of  metal.  After  pouring  these 
test  bars,  about  20  pounds  of  this  metal  was  then 
poured  into  a  hand  ladle,  the  bottom  lining  of  which 
was  composed  of  fire  clay  mixed  with  about  two  and 


224  METALLURGY    OF    CAST    IRON. 

one-half  ounces  of  pulverized  brimstone.  The  20 
pounds  of  metal  was  allowed  to  stand  in  the  hand  ladle 
about  forty  seconds,  when  two  test  bars  were  poured, 
both  of  which,  when  broken,  agreed  very  closely  in 
strength.  The  stronger  one  of  these  is  recorded  as 
test  bar  No.  19.  All  of  these  test  bars  are  of  the 
round  form  and  cast  on  end.  It  will  be  seen  by  a  com- 
parison of  the  analysis  of  these  two  test  bars,  Nos. 
1 8  and  19,  that  the  latter  absorbed  or  contains  .096 
more  sulphur  than  the  bar  which  was  poured  direct 
from  the  cupola,  and  .160  more  than  the  iron  charged. 
In  breaking  these  bars  it  will  be  seen  that  the  high 
sulphur  bar  No.  19  stood  540  pounds  more  than  the 
direct  bar  No.  18,  thereby  asserting  that  sulphur  will 
strengthen  iron.  But  whether  or  not  such  an  increase 
in  strength  in  test  bars  could  be  beneficial  to  castings 
will  depend  largely  upon  the  internal  strains  which 
the  addition  of  sulphur  causes  in  increasing  the  con- 
traction. This  can  be  seen  by  Table  No.  31,  in  which 
the  sulphur  bar  will  be  seen  to  have  contracted  1-32 
inch  more  than  the  direct  bar.  I  have  conducted  a 
number  of  experiments  in  adding  sulphur  to  the  molten 
metal  with  iron  ranging  from  one  per  cent,  to  two  per 
cent,  of  silicon,  and  have  found  it  to  increase  the 
strength  of  the  test  bars.  This  is  to  Be  expected  sim- 
ply from  the  fact  that  sulphur  increases  the  com- 
bined carbon.  With  two  per  cent,  in  silicon  in  test- 
ing one-and-one-eighth-inch  round  bars,  I  have 
found  it  to  increase  the  strength  only  from  150  to  200 
pounds,  thus  showing  that  the  higher  the  silicon, 
the  less  effect  the  sulphur  has  in  strengthening  the 
iron  to  the  limit  of  its  absorption.  Views  of  the  frac- 
ture of  the  above  bars,  described  in  Tables  31  and 


AFFINITY    OF    IRON    FOR    SULPHUR.  225 

32,  can  be  seen  in  Fig.  102,  Chapter  LX.,  page  473. 

Iron  absorbs  sulphur  most  readily  from  the  fuel 
when  being  re-melted.  I  have  records  of  its  increasing 
the  percentage  of  sulphur  in  one  re-melt  from  .030  to 
.105,  with  fuel  below  one  per  cent,  of  sulphur,  and  the 
iron  charged  averaging  about  1.60  of  silicon. 

It  is  no  uncommon  occurrence  for  iron  to  be  as  high 
as  three  to  four  per  cent,  in  silicon  and  to  contain  as 
high  as  .200  in  sulphur,  thereby  proving  that  iron  can 
be  high  in  sulphur  and  at  the  same  time  high  in 
silicon. 

While  sulphur  can  increase  the  strength  of  iron  up 
to  a  certain  limit,  it  is  of  such  character  as  to  greatly 
decrease  resistance  to  deflection  or  elasticity  of  iron. 
On  this  account  I  would  say  that  in  such  castings  as 
chill  rolls  and  ingot  moulds,  which  have  their  surface 
and  body  subjected  to  high  heat,  requiring  conditions 
in  metal  to  admit  of  expansion  and  contraction  follow- 
ing each  other  closely,  excessive  sulphur  is  to  be 
guarded  against,  and  in  light  or  medium  machinery  it 
is  injurious  by  increasing  the  contraction  and  chill  or 
hardness  of  castings.  The  former  element  is  injurious 
in  causing  internal  strains,  and  the  latter  in  causing 
castings  to  be  harder  than  desired. 

It  is  now  (1901)  universally  conceded  that  iron  has 
a  great  affinity  for  sulphur,  and  that  it  is  an  element 
often  to  be  feared  by  both  furnacemen  and  founders. 
The  distribution  of  the  first  two  editions  of  this  work 
has  done  much  in  advancing  the  universal  recognition 
of  these  two  facts. 


CHAPTER  XXXI. 

EFFECTS   OF    ADDING    PHOSPHORUS    TO 
MOLTEN  IRON. 

This  chapter  presents  results  which  the  author  ob- 
tained by  experimenting  with  phosphorus  added  to 
molten  iron.  Some  of  these  experiments  were  orig- 
inally presented  in  a  paper  by  the  author  to 
the  Pittsburg  Foundrymen's  Association,  January, 
1898.  In  conducting  them  the  metal  was  caught 
at  the  cupola  in  a  ladle  holding  about  one  hundred 
and  fifty  pounds.  This  was  carried  to  the  moulds  and 
about  thirty  pounds  was  poured  into  a  hand  ladle  into 
which  sticks  of  phosphorus  had  been  placed  before 
pouring  the  metal,  and  then  again  by  placing  the 
sticks  on  top  of  the  metal.  This  mixture  was  stirred 
with  a  small  rod  until  the  phosphorus  was  thought  to 
have  been  all  absorbed.  In  a  natural  way  phosphorus 
increases  the  fluidity  and  life  of  molten  metal,  and 
can  greatly  weaken  it.  By  the  above  method  results 
are  reversed  and  the  metal  made  to  lose  its  fluidity 
and  solidify  rapidly,  and  give  stronger  iron.  For 
castings  that  can  be  poured  with  dull  metal  the  ad- 
dition of  phosphorus  may  often  be  very  beneficial  in 
giving  strong  castings.  The  letters  P.T.  at  the  left  of 
Table  33,  page  231,  designate  the  tests  having  the  phos- 
phorus added  to  the  metal  when  in  the  ladle,  and  P.  B. 
its  being  placed  on  the  bottom  of  the  ladle  and  the  metal 


EFFECTS  OF  ADDING  PHOSPHORUS  TO  MOLTEN  IRON.      227 

poured  onto  it,  while  R.  I.  refers  to  the  metal  free  of 
the  phosphorus  addition. 

All  the  bars  were  cast  on  end  and  tested  1 2  inches 
between  supports.  Those  of  tests  Nos.  i  and  2  were 
made  from  patterns  \Yz  inches  in  diameter  and  the 
balance  from  1^6  inches  diameter.  The  strength 
column  of  Table  33  shows  the  breaking  load  reduced 
to  strength  per  square  inch  by  the  method  shown  on 
page  476.  Each  test  shown  is  an  average  of  from  two 
to  four  bars.  Tensile  tests  were  made  of  tests  Nos.  i, 
2,  3,  4,  5,  and  6.  The  i^-inch  bars  with  the  phos- 
phorus addition  of  No.  i  pulled  27,640  pounds,  whereas 
the  regular  broke  at  15,130  pounds,  showing  that  the 
addition  of  phosphorus  nearly  doubled  the  strength  of 
the  iron  in  this  case.  Test  No.  3,  i  ^4 -inch  bars,  aver- 
aged 23,790  pounds,  whereas  No.  4  averaged  17,617 
pounds.  Bars  of  test  No.  5  averaged  26,070,  and 
those  of  No.  6  16,890  pounds.  A  study  of  Table  33 
will  show  that  all  tests  were  greatly  strengthened  by 
the  slight  addition  of  phosphorus  to  the  molten  iron, 
excepting  test  No.  10.  The  author  believes  this  is  due 
to  the  high  silicon  iron. 

A  study  of  the  analysis  of  Table  33  shows  that  the 
addition  of  phosphorus  drove  out  or  decreased  the 
silicon,  manganese,  and  total  carbon,  the  phosphorus 
acting  as  a  flux  to  drive  out  oxides  or  impurities  so  as 
to  leave  a  greater  percentage  of  metallic  iron  in  the 
higher  phosphorus  iron  than  existed  in  the  regular  iron, 
as  is  seen  in  the  last  column  of  the  analysis  at  T.  I. 
The  effect  of  decreasing  impurities,  as  shown,  is  in 
keeping  with  the  treatment  of  Chapter  XXXIV.  Aside 
from  the  decrease  of  the  impurities  we  find  that  the 
increase  of  combined  carbon  shown,  caused  by  increas- 


228  METALLURGY    OF    CAST    IRON. 

ing  the  phosphorus,  is  also  a  factor  that  must  have  an 
effect  in  strengthening  the  iron.  The  increase  of 
combined  carbon  causes  greater  contraction  but  less 
chill,  a  peculiarity  due,  no  doubt,  to  the  fact  that  hot 
metal  will  chill  deeper  than  dull  metal,  as  shown  in 
Chapter  LVI.  However,  the  ends  cast  against  chills 
were  very  dense  and  hard.  Tests  Nos.  i  to  6,  with 
their  analyses,  were  made  by  Dr.  R.  Moldenke  at  the 
McConway  &  Torley  Co.,  Pittsburg,  Pa.,  and  tests 
Nos.  7  to  ii  by  the  author,  and  the  analyses  by  Mr. 
H..E.  Diller  at  the  Pennsylvania  Malleable  Co.,  Pitts- 
burg,  Pa. 

There  are  several  methods  of  adding  phosphorus  to 
molten  iron.  The  simplest  plan  consists  in  introducing 
the  phosphorus  with  the  hand  or  with  tongs.  There 
need  be  no  fear  of  the  dampness  on  the  sticks  as  they 
are  taken  from  the  water,  for  as  long  as  water  is  on  top 
of  the  metal  no  harm  can  result.  Care  should  be  taken 
in  handling  phosphorus  by  hand  to  do  it  quickly,  as 
it  ignites  in  a  little  more  than  one  minute  when 
exposed  to  the  air  and  serious  burns'have  resulted  from 
careless  handling.  Another  method  used  by  some  is 
to  take  a  rod,  to  one  end  of  which  is  secured  a  dried 
clay  or  graphitic  core  having  a  ^s-inch  hole  extending 
into  one  end  six  to  seven  inches  deep.  Into  this  hole 
the  phosphorus  stick  is  inserted  and  held  by  means  of 
sticking  a  few  strips  of  tin  or  copper  in  the  vacant 
space.  Still  another  plan  is  to  take  a  piece  of  gas  pipe 
about  three  feet  long,  with  a  hole  a  little  larger  than 
the  sticks  of  phosphorus,  and  after  the  phosphorus  is 
inserted  place  a  plug  of  tin  about  one-eighth  of  an  inch 
thick  to  fit  tightly  into  the  end  of  the  pipe.  While 
introducing  the  end  of  the  pipe  into  the  molten  metal 


EFFECTS  OF  ADDING  PHOSPHORUS  TO  MOLTEN  IRON. 


FIG.   49, — PAN    FOR   DRYING 
PHOSPHORUS. 


the  tin  will  melt  quickly  and  allow  the  phosphorus  to 
diffuse  through  the  metal.  To  prevent  the  fumes  of 
phosphorus  escaping  through  the  upper 
end  of  the  pipe  a  plug  of  iron  should 
be  driven  into  the  pipe  some  distance 
to  permit  the  insertion  of  the  phos- 
phorus. Where  several 
sticks  of  phosphorus  are 
best  inserted  in  the  metal  at 
one  time,  a  device  as  seen 
in  Fig.  50  may  often  be 
used.  After  quickly  insert- 
ing the  sticks  of  phosphorus 
into  the  receptacle  A,  Fig. 
50,  they  are  permitted  to 
remain  a  few  seconds  until  dry  and  showing  signs 
of  igniting,  after  which  the  receptacle  is  tilted  gently 
to  slide  into  the  molten  metal  and  held  there  until 
the  phosphorus  has  been  absorbed.  A  plan  fol- 
lowed by  some  to  permit  sticks  of  phosphorus  being 
handled  without  danger  of  taking  fire  is,  to  first  pre- 
pare the  sticks  by  placing  them  in  a  dilute  solution 
of  sulphate  of  copper,  or  a  few  crystals  of  blue  vitriol 
placed  in  water  held  in  a  stone  jar,  for  a  period  of 
thirty  minutes  or  so.  This  process  deposits  a  coating 
of  copper  on  the  sticks  of 
phosphorus,  which  permits 
them  to  be  handled  without 
danger  of  taking  fire  as 
long  as  the  copper  coating  is 
not  disturbed.  In  remov-  The  space  between  the  iron  rod  and 

ing     the     phosphorus     from  retort  is  made  tight  with  a  cement  of 
,  1  .,  .  mineral  paint  mixed  to  a  stiff  paste 

the  solution  in  the  jar  some  whh  linseed  oil. 


FIG.    5O. — RETORT 

AND     CRUCIBLE    FOR 

PHOSPHORIZING. 


230  METALLURGY    OF    CAST    IRON. 

place  the  sticks  on  blotting  paper  resting  on  wire 
netting,  supported  in  a  pan  four  to  six  inches  deep, 
containing  about  two  inches  of  water,  as  shown  by 
Fig.  49.  This  pan  should  have  a  cover,  which  can  be 
closed  air  tight  in  case  the  phosphorus  takes  fire.  This 
is  a  method  which  was  presented  by  Mr.  Max  H.  Wick- 
horst  in  a  paper  before  the  Western  Foundry  men's 
Association,  March  17,  1897.  Phosphorus  can  be  ob- 
tained from  almost  any  druggist,  and  comes  in  the 
form  of  sticks  about  three-quarters  of  an  inch  in 
diameter  and  four  inches  long,  weighing  about  two 
ounces,  and  is  kept  in  corked  bottles,  etc. ,  of  water  hold- 
ing about  half-a-dozen  sticks  of  phosphorus.  It  has  to 
be  kept  in  water  on  account  of  its  being  a  substance 
which  will  melt  at  about  in  degrees  F.,  and  ignite 
of  its  own  accord  if  left  exposed  a  few  minutes  to  the 
drying  influence  of  the  air. 

Another  discovery  of  importance  revealed  by  these 
tests  is  found  in  Table  34.  This  shows  that  an  increase 
of  phosphorus  increases  the.  fusibility  of  iron.  This 
knowledge  is  valuable  in  showing  that  the  lower  the 
phosphorus  the  better,  in  castings  such  as  annealing 
boxes  and  pots,  ingot  moulds,  grate  bars,  etc. ,  which  are 
required  to  stand  high  temperatures.  Up  to  the  time 
the  author  presented  his  tests  (see  Table  34)  there  was 
no  information  obtainable  designating  what  percentage 
of  the  metalloids  was  best  in  fire-resisting  castings. 
With  the  information  to  be  gleaned  from  pages  352  and 
351  it  will  be  seen  that  the  lower  the  combined  carbon, 
sulphur,  and  phosphorus,  the  better  the  iron  to  resist 
Tieltmg  or  high  temperatures.  This  knowledge  is  very 
valuable  in  assisting  to  make  mixtures  for  castings  that 
are  expected  to  resist  high  or  melting  temperatures. 


EFFECTS  OF  ADDING  PHOSPHORUS  TO  MOLTEN  IRON.     23! 

TABLE   33. — COMPARATIVE   TRANSVERSE    PHOSPHORUS    IRON    TESTS    AND 

ANALYSES. 


Test 
No. 

Defl. 

Str'gt 

Phos. 

Sil. 

Sul. 

Man. 

G.  C. 

C.  C. 

T.  C. 

T.I. 

ist  cast,  P.  T. 

i 

•125 

4-482 

.161 

1.48 

•03 

•65 

2.10 

1.85 

3-95 

6.271 

ist  cast,  R.  I. 

2 

.08 

2,463 

.088 

1-53 

•03 

.68 

2.90 

1.20 

4.10 

6.428 

2d  cast,  P.  T. 

3 

•15 

3,329 

.136 

.46 

•03 

.58 

1.  80 

2-44 

4.24 

6.446 

2d  cast,  R.  I. 

4 

.12 

2,064 

•095 

.48 

•03 

.60 

2.48 

1.84 

4-32 

6.525 

3d  cast,  P.  T. 

5 

•115 

3-087 

•  173 

•32 

•03 

•63 

1.84 

2.19 

4-03 

6.183 

3d  cast,  R.  I. 

6 

.10 

2,170 

•093 

•37 

•03 

•65 

2.66 

1.50 

4.16 

6.303 

4th  cast,  P.  B. 

7 

•135 

2,322 

.144 

.20 

.065 

•63 

3-30 

•44 

3-74 

5-779 

4th  cast,  P.  T. 

8 

•125 

2,001 

.121 

.16 

.068 

.64 

3-37 

•43 

3-8o 

5.789 

4th  cast,  R.  I. 

9 

.090 

1,740 

.090 

.40 

.070 

•65 

3-45 

.40 

385 

6.060 

5th  cast,  P.  U. 

10 

.070 

1,386 

.280 

443 

.090 

-36 

2.20 

.82 

3-02 

8.180 

5th  cast,  R.  I. 

ii 

.070 

1,366 

.213 

4-45 

.110 

.41 

3-06 

•03 

3-09 

8.273 

TABLE    34. — COMPARATIVE    FUSION     TESTS    OF     BARS    RECORDED    NOS.    I 
TO    6,    TABLE    33. 


ist  Cast. 

2nd  Cast. 

3rd  Cast. 

Diameter  of 

Rolls. 

\Yz  ins. 

2-%  ins. 

\Yz  ins. 

2%  ins. 

1%  ins. 

2%  ins. 

Time  of  dipping.... 

2:00 

3:00 

2:00 

3:00 

2:00 

3:00 

Time    of    total 

fusion     lower 
phosph'us  bars_ 
Time    of    total     ~) 

2:03^ 

3:04% 

2:03 

3:o4}£ 

2:03^ 

3:05 

fusion  higher 
phosph'us  bars 
Differ  'ce  in  time 
of  melting  

2:02^ 
i  mill. 

3:03^ 
ij<  mill. 

2:02)4 
3£  mill. 

3:03* 
\Y±  mill. 

2:02 
i  min. 

3»3^ 
il/z  min. 

The  plan  followed  in  testing  the  fusibility  of  the  iron 
and  phosphorus  alloys  in  Table  34  and  shown  by  Fig. 
51,  next  page,  displays  two  sizes  of  fusing  test  speci- 
mens. At  H  and  K,  on  the  left,  are  bars  i  %  inches  in 
diameter  by  1 2  inches  long,  connected  by  a  rod  M.  H 
and  K,  on  the  right  of  Fig.  49,  are  test  specimens  2^6 
inches  in  diameter  by  6  inches  long.  In  casting  these 
test  specimens  one  was  poured  with  a  regular  cupola 
metal,  and  the  other  with  the  metal  after  the  phos- 


METALLURGY    OF    CAST    IRON. 


phorus  had  been  added  in  the  manner  described.  By 
using  a  hook  as  at  P,  to  let  the  test  specimens  sink 
into  a  ladle  of  molten  metal,  it  will  be  readily  seen 
that  both  bodies  H  and  K  must  be  subjected  to  exactly 
the  same  conditions  of  heat,  etc. ,  in  testing  their  fusi- 


H 


FIG.    51. 

bility.  By  such  a  plan,  if  H  melts  down  before  K  we 
have  positive  proof  that  H  possesses  a  lower  fusing 
point  than  K.  The  author  has  found  this  a  very 
simple  and  inexpensive  plan  to  test  the  fusion,  of  mix- 
tures, or  the  effect  of  any  one  of  the  metalloids  on  the 
fusibility  of  iron.  Another  good  plan,  devised  and 
used  by  the  author,  is  shown  in  Figs.  87  and  88,  pages 
416  and  417. 


CHAPTER  XXXII. 

EFFECTS  OF  VARIATIONS  IN  MANGANESE 
ON  DIFFERENT  GRADES  OF  IRON. 

This  chapter  presents  the  results  of  tests  made  by 
the  author  with  a  wide  range  of  different  grades  of 
iron,  having  varying  percentages  of  manganese,  to 
give  information  that  will  be  applicable  to  nearly  all 
classes  of  founding.  The  tests  far  surpass  anything 
previously  presented  for  covering  a  broad  field,  and 
were  originally  presented  by  the  author  to  the  Ameri- 
can Foundrymen's  Association  Convention  at  Buffalo, 
N.  Y.,  June,  1901.  The  results  shown  in  Tables  35 
and  36  pages  236  and  237,  verify  some  of  the  properties 
attributed  to  manganese  and,  the  writer  believes, 
amplify  our  knowledge  of  its  effect  on  cast  iron 
considerably.  We  shall  first  outline  the  methods  of 
physical  testing  followed  in  this  work. 

The  breaking  strength  and  deflection  given  in  col- 
umns 3  and  4,  Table  35,  are  each  the  average  of  about 
four  tests,  two  of  the  tests  being  from  i^-inch 
round  bars  cast  on  end,  and  two  from  i-inch  square 
bars  cast  flat,  and  used  for  obtaining  the  contraction 
and  chill.  All  bars  were  tested  12  inches  between 
supports. 

The  contraction  tests  recorded  in  column  5,  Table  35, 
were  obtained  by  casting  square  bars  A  and  B  in  a 
frame  C,  Fig.  52.  The  contraction  was  measured  by 


234  METALLURGY    OF    CAST    IRON. 

a  graduated  wedge  D,  the  thickness  of  the  point  at 
which  it  settled  between  the  bars  and  frame  being 
measured  by  a  micrometer,  as  at  V,  Fig.  55.  The  bars 
were  i  inch  square  by  24  inches  long  and  poured  by 
top  gates,  as  shown.  The  chill  was  obtained  by  break- 
ing off  a  piece  at  the  ends  as  shown  at  E,  Fig.  55. 

To  obtain  the  hardness  tests,  the  writer  arranged  a 
drill  press,  as  shown  in  Fig.  53.  A  bicycle  cyclom- 
eter was  attached  to  the  upper  body  of  the  frame,  at 
F,  and  then  a  light  sheet  iron  ring  was  bolted  to  the 
upper  shaft  G,  with  an  arm  as  at  H.  This  arm  came 
in  contact  with  the  cyclometer  at  every  revolution  of 
the  shaft  G,  and  recorded  the  exact  number  of  revolu- 
tions made  in  a  stated  time,  by  a  watch  held  in  the 
hands  of  the  operator  as  seen  at  I.  In  order  to  apply 
a  constant  pressure  of  the  drill  J  on  the  test  piece  K, 
a  weight  L  was  suspended  from  the  lower  arm  M,  by 
a  wire,  at  a  given  distance  from  the  end,  as  shown. 
Three  revolutions  of  the  shaft  G,  equalled  two  of  the 
drill.  The  machine  could  be  stopped  in  a  second  by  a 
lever  at  M.  The  same  ^-inch  drill  was  used  for  all 
tests,  testing  the  softer  specimens  first,  and  the  harder 
ones  last.  The  drill  was  kept  of  a  uniform  sharpness 
for  the  bars  of  each  cast.  The  drill  ran  60  seconds  for 
each  test  and  the  speed  of  the  shaft  G  varied  from  35 
to  37  revolutions.  An  average  of  36  revolutions  was 
allowed  in  computing  the  depth  of  the  holes  made  in  60 
seconds  and  recorded  in  column  7.  The  tests  obtained 
by  this  drill  press  proved  very  satisfactory.  To  obtain 
the  depth  of  the  hole  a  wooden  pin  O,  Figs.  54  and  55, 
.  was  set  into  the  drilled  holes,  as  seen  at  P,  and  a  steel 
pin  R,  pressed  into  the  wooden  pin  on  a  level  with  the 
top  of  the  test  specimen,  as  shown  at  R.  After  the 


EFFECTS    OF    VARIATIONS    IN    MANGANESE.  235 


236 


METALLURGY    OF    CAST    IRON. 


t^Ei  *? 

u 

No.  of 
test 

2 

Iron  used. 

3 

Breaking 
Strength. 

4 

Deflec- 
tion 

5 

Contrac- 
tion. 

6     , 
Chill. 

7 

Hard- 
ness. 

8 

Struc- 
ture. 

3  - 

i.n 

Foundry  pig. 

2,169  lbs. 

.107 

.180" 

None 

•572 

4 

l| 

2. 

Mn.  in  cupola 

2,268  Ibs. 

.110 

.231 

None 

.122 

5 

flri 

•     3- 

Foundry  pig. 

1,715  lbs. 

.101 

.198 

None 

.625 

5 

Wfc 

4- 

Mn.  in  cupola 

1,  808  Ibs. 

.082 

•237  " 

Slight 

•415 

5 

«*i 

5- 

Charcoal  pig. 

i  ,5  ro  Ibs. 

•075  ' 

.276 

None 

•438 

3 

£ 

6. 

•Mn.  in  cupola 

1,822  Ibs. 

.090 

.291 

None 

.410 

4 

S 

7- 

Mn.  in  cupola 

1,654  !bs. 

.072" 

•315  " 

.025 

.248 

5 

K 

8. 

Mn.  in  ladle. 

r,577  lbs. 

.077" 

.284  " 

None 

.506 

2 

*»     Tf 

9- 

Foundry  pig. 

i,  428  lbs. 

.101 

11 
•125 

None 

•730 

3 

I* 

10. 

Mn.  in  cupola 

i,  690  Ibs. 

,102 

.204 

Slight 

.600 

5 

ii. 

Ma.  in  ladle 

i,  763  lbs. 

.083  " 

.161   " 

None 

•705 

4 

12. 

Foundry  pig. 

1,652  lb.s. 

.105 

.216 

None 

•553 

3 

o 

13- 

Mn.  in  cupola 

2,269  lbs. 

.130 

.260  " 

Slight 

.107 

6 

14- 

Mn.  in  ladle 

i,  995  lbs. 

.100 

.229   " 

None 

•532 

4 

a 

'5- 

Mn.  in  ladle 

2,016  lbs. 

.IOO 

.246    " 

None 

•578 

4 

16. 

Mn.  in  ladle 

2,122  lbs. 

•095  " 

.279  " 

Slight 

.490 

5 

(0 

17- 

Foundry  pig. 

1,888  lbs. 

.100 

.309 

None 

•347 

3 

£ 

18. 

Mn.  in  cupola 

i,  794  lbs. 

.097  " 

.320  " 

None 

.282 

3 

j 

19- 

Mn.  in  cupola 

i  ,845  lbs. 

.080  " 

•330  " 

.062 

.204 

3 

H 

20. 

Mn.  in  ladle 

1,970  lbs. 

.102" 

.309" 

None 

•314 

3 

21. 

Charcoal  pig. 

2,355  lbs. 

'/ 

•095 

•339 

.128 

.385 

7 

O 

22. 

Mn.  in  cupola 

2,331  lbs. 

.090 

•348  " 

.166 

•244 

7 

1 

23- 

Mn.  in  ladle 

2,394  lbs. 

.IOO 

•341  " 

•055 

•450 

5 

H 

24- 

Mn.  in  ladle 

2,310  lbs. 

.102." 

•  340  " 

.040 

.428 

5 

3°° 

25. 

Bessemer  pig 

1,701  lbs. 

.125 

.226  " 

.300 

.420 

3 

E* 

26. 

Mn.  In  cupola 

1,497  lbs. 

•055  " 

.242  " 

All 

White 

White 

o> 

27- 

Charcoal  iron. 

1,570  lbs. 

.052 

.401. 

1-375 

.040 

Mottled 

| 

28. 

Mn.  in  cupola 

1,082  lbs. 

.046 

.427  " 

All 

White 

White 

S 

29. 

Mn.  in  ladle 

i,  772  lbs. 

.100" 

.326  " 

I.  IOO 

.242 

3 

EC 

30. 

Mn.  in  ladle 

2.066  lbs. 

.095" 

-322  " 

•83° 

.222 

3 

EFFECTS    OF    VARIATIONS    IN    MANGANESE. 


237 


9 
Sil. 

10 
Sul. 

II 

Mang. 

12 

Phos. 

«3 
C.C. 

'4 
G.C. 

15 
Total  C. 

i 

No.  of 
test 

4-53 

.025 

•52 

•  '94 

.06 

2.98 

3-04 

I. 

4.40 

.018 

6.12 

.178 

.28 

2.61 

2.89 

2. 

4-5i 

•031 

.48 

•  203 

.07 

3-'9 

3-26 

3- 

4.41 

.023 

2.62 

.198 

•23 

3-01 

3-24 

4- 

4-45 

.no 

.41 

•  213 

•03 

3-o6 

3-09 

5- 

4-3' 

.067 

1.09 

.210 

•05 

3-io 

3->5 

6. 

4-30 

.032 

4.09 

.192 

.16 

3-09 

3-25 

7- 

4-52 

.108 

•5i 

.211 

•03 

3-05 

3-o8 

8. 

3-92 

.034 

•44 

.164 

.06 

3-35 

3-4« 

9- 

3-88 

.029 

i.  08 

.156 

•'9 

3-16 

3-35 

10 

3-88 

.029 

.76 

.162 

.08 

3-29 

3-37 

ii 

3-88 

.031 

•49 

.194 

.09 

S-o6 

3-15 

12 

3-53 

.020 

3-53 

•152 

•30 

2.87 

3-17 

13 

3-82 

,026 

.68 

•'93 

.11 

3-22 

3-33 

'4 

3-63 

.025 

•8? 

.191 

.11 

3-39 

3-50 

'5 

3-74 

.025 

1.  18 

.192 

.10 

3-03 

3-13 

16 

2-47 

.O3O- 

•97 

•255 

.42 

3-44 

3-86 

i? 

2.40 

.022 

2.26 

.250 

•45 

3-38 

3.83 

ii 

2.41 

.022 

3-7i 

•231 

•47 

3-25 

3-72 

»9 

2.56 

.038 

1.16 

•254 

.40 

3-44 

3-84 

20 

1.88 

•039 

.26 

•458 

.61 

2.92 

3-53 

21 

1.69 

.036 

2-43 

•435 

.64 

2.82 

3.46 

22 

1.89 

•035 

.67 

•455 

50 

3-02 

3-52 

23 

2.06 

•033 

.78 

•457 

•47 

3-" 

3^58- 

24 

1-34 

,076 

•54 

.087 

.61 

3-28 

3-89 

25 

1.30 

.061 

5-ii 

.076 

3-4i 

•i? 

3-58 

26 

•53 

.070 

•34 

.407 

.    i-i4 

2.66 

3-8o 

27 

•63 

.042 

2.84 

•365 

3-53 

•15 

3-68 

28 

.69 

.068 

.69 

.420 

•49 

3-4« 

3-90 

29 

•74 

.060 

•74 

.424 

.62 

3-28 

3-90 

30 

238  METALLURGY    OF    CAST    IRON. 

pin  O  was  removed  it  was  set  on  a  level  clean  surface, 
a  wedge  T  passed  along  until  it  was  stoppd  by  a  pin, 
as  at  U.  The  distance  the  wedge  passed  under  the  pin 
U  was  measured  by  a  micrometer  at  V,  Fig.  55.  The 
depth  of  such  holes  could  also  be  measured  by  filling 
them  with  water  and  measuring  it  with  a  small  gradu- 
ate, shown  at  W,  Fig.  55.  The  structure,  column  No. 
8,  is  given  merely  to  denote  distinctions  as  made  by 
the  eye  in  judging  the  relative  size  of  the  crystals  or 
grain  of  the  fracture.  For  example,  No.  2  stands  for 
what  would  be  expected  of  the  grain  in  <a  piece  of  true 
No.  2  iron,  and  so  on  up  with  closer  iron  in  the  higher 
numbers. 

The  iron  was  melted  in  the  twin  shaft  cupola  seen 
in  Fig.  56,  the  operation  of  which  is  explained  in 
pages  325  to  327.  The  use  of  such  a  cupola  is 
the  most  reliable  one  for  making  comparative  tests, 
which  involve  delicate  observations  and  affords  a 
remarkably  uniform  conditions  of  fuel,  blast,  heat,  etc. , 
necessary  to  discover  the  true  effects  of  changes  in  the 
elements  composing  cast  iron.  The  fact  that  the  tests 
in  Table  35  were  obtained  with  the  use  of  the  cupola, 
Fig.  56,  gives  the  writer  greater  confidence  in  the 
results  shown  than  he  could  place  in  any  others 
obtained  in  the  ordinary  way  of  making  separate  com- 
parative tests,  that  is,  having  one  heat  taken  off  one  day 
and  another  some  other  day,  with  the  differences  in 
fuels,  blast,  and  heat  conditions  that  usually  exist  in 
making  heats  in  ordinary  cupolas. 

In  charging  the  cupola,  Fig.  56,  small  pieces  from 
the  same  pig  were  placed  in  each  compartment  and 
the  ferro-manganese  placed  on  one  side  only.  For 
the  second  and  fifth  heats,  shown  in  Table  35,  two 


EFFECTS    OF    VARIATIONS    IN    MANGANESE.  239 


FIG.    53. 


(X 



Ov 

-» 

0 

--—  «• 

—  N 

-—  R 

p4 

^s^ 

•'•     - 

—  s 

^^-r-T-n-Vr-rT-^ 

?**- 

_..)-]       +-r=z 

N^, 

Measuring    face     plate    table.                                                                 ! 

FIG.    54. 


240 


METALLURGY    OF    CAST    IRON. 


EFFECTS    OF    VARIATIONS    IN    MANGANESE. 


241 


charges  of  pig 
iron  with  differ- 
ent percentages 
of  manganese 
were  made  in  the 
side  containing 
the  manganese. 
The  weight  of 
the  charges  was 
from  45  to  60 
pounds  of  iron 
with  a  range  of 
one  to  three 
pounds  of  man- 
ganese mixed 
with  the  charges. 
Heats  Nos.  i,  2, 
4,  5,  and  6  were 
made  of  Foundry 
pig  iron.  Heats 
Nos.  3,  7,  and  9 
of  Charcoal  pig 
iron,  and  heat 
No.  8  of  Besse- 
mer pig  iron.  The  analysis  of  the  ferro-manganese 
was  silicon  1.65,  manganese  80.34,  phosphorus  .354, 
total  carbon  5.85,  and  no  sulphur. 

In  adding  manganese  to  the  metal  in  the  ladle  (this 
metal  was  always  that  coming  from  the  side  of  the 
cupola  free  from  the  ferro-manganese  mixture),  it  was 
broken  to  the  size  of  a  pea  and  thrown  gently  on  top 
of  the  molten  metal,  and  then  stirred  well  with  a  half- 
inch  rod  until  all  melted  and  in  mixture  with  the  iron, 


>f2  METALLURGY    Ot    CAST    IRON. 

which  came  down  as  hot  as  is  generally  required  for 
pouring  stove  plate. 

The  210  analyses  shown,  along  with  the  extra  work 
of  cross-checking,  were  made  by  Mr.  H.  E.  Diller, 
of  the  Pennsylvania  Malleable  Co.,  Pittsburg,  Pa. 
The  writer  and  the  association  are  greatly  indebted  to 
Mr.  Diller  for  his  work  in  making  gratuitously  such  a 
large  number  of  analyses.  We  have  also  in  this  con- 
nection to  thank  Prof.  A.  W.  Smith,  of  the  Case  School 
of  Applied  Science,  Mr.  Frank  L.  Crobaugh,  proprietor 
and  expert  of  the  Foundrymen's  Laboratory,  Cleve- 
land, O.,  and  D.  K.  Smith,  chemist,  Claire  Furnace, 
Sharpsville,  Pa. ,  for  their  able  services  in  checking  the 
combined  and  graphitic  carbon  determinations,  a  work 
done  in  order  to  increase  the  confidence  in  the  deter- 
minations of  carbon. 

The  moulding,  casting,  and  testing  of  the  bars  were 
all  performed  chiefly  by  the  writer,  as  he  believes 
experimentors  should  leave  as  little  to  other  parties  as 
possible.  To  give  an  idea  of  the  costs  in  making 
experiments,  it  can  be  said  that  if  the  labor  and 
material  involved  in  this  series  of  experiments  were 
computed  at  the  lowest  ordinary  rates,  the  cost  would 
reach  about  three  hundred  dollars. 

In  a  general  way,  the  addition  of  manganese  to  the 
iron  in  the  cupola  increases  the  hardness  by  raising  the 
percentage  of  combined  carbon,  which  means  greater 
contraction  and  chill,  with  a  decrease  in  deflection  and 
elasticity.  While  it  is  true  that  manganese  in  cupola 
mixtures  has  the  tendency  just  mentioned,  a  study  of 
the  tests  given  in  Tables  35  and  36  will  show  that  the 
variation  of  manganese  generally  existing  in  any  one 
grade  of  pig  iron  will  have  very  little  if  any  effect  on 


EFFECTS    OF    VARIATIONS    IN    MANGANESE.  243 

the  physical  properties  of  the  casting",  something  which 
is  entirely  different  from  the  changes  due  to  the  silicon 
and  sulphur  of  irons  coming  from  any  one  mixture  of 
ores,  flux,  and  fuel.  A  good  test  demonstrating  this 
point  is  found  in  heat  No.  6,  which  has  2.47  silicon  in 
Foundry  pig  when  remelted.  Here  we  find  that  an 
increase  from  .97  to  2.26  —  a  difference  of  over  1.25 
per  cent.  —  of  manganese  in  pieces  of  the  same  pig 
does  not  cause  a  chill  in  the  ends  of  the  square  bars, 
when  tested  as  at  E,  Fig.  55,  and  has  only  a  difference 
of  .on  in  the  contraction.  By  increasing  the  manga- 
nese still  higher  until  we  have  3.71  — nearly  3  per  cent, 
of  an  increase  —  we  then  obtain  a  chill  of  only  .062  in 
the  ends  of  the  bars,  as  at  E,  Fig.  55,  and  a  difference 
of  only  .021  in  the  contraction  over  that  found  in  the 
test  bars  free  of  the  ferro-manganese  mixture.  Then 
again,  the  hardness  tests,  column  7,  show  a  difference 
of  but  .065  and  .143  in  the  depth  of  the  drilled  holes, 
as  at  P,  Figs.  54  and  55,  with  the  two  variations  in 
manganese.  Still  further,  the  structure,  column  8,  of 
the  gray  body  exhibits  no  difference  to  the  eye. 
Another  point  shown  by  this  heat  comes  from  the 
manganese  placed  on  the  molten  metal  in  the  ladle. 
Here  we  find  that  an  increase  of  .19  in  the  percentage 
of  manganese  has  made  no  difference  in  the  contraction 
and  a  variation  of  but  .033  in  the  depth  in  the  hardness 
test.  This  shows  that  the  addition  of  manganese  in 
the  ladle  tends  to  slightly  increase  the  hardness,  which 
is  contrary  to  what  we  have  generally  been  led  to 
believe  by  writers  in  the  past.  We  are  not  confined  to 
this  one  test  to  modify  views  of  the  past  on  this  point, 
as  the  same  result  is  also  shown  in  heats  Nos.  4,  5,  and 
6.  However,  when  we  get  to  low  silicon  irons,  as  in. 


244  METALLURGY  OF  CAST  IRON. 

heats  Nos.  7  and  9,  we  find  that  manganese  in  the  ladle 
is  very  effective  in  softening  the  iron,  or  very  sensi- 
tive in  producing  radical  changes. 

The  effect  of  manganese  on  the  strength  of  cast  iron 
has  a  tendency,  as  a  rule,  to  make  iron  stronger.  In 
adding  manganese  to  molten  metal,  the  iron  should 
never  be  dull,  but  as  hot  as  practicable,  in  order  that 
all  the  manganese  may  be  melted  in  such  a  manner 
that  a  homogeneous  mixture  may  result.  Where  iron 
is  dull,  a  fracture  may  often  show  little  bright  spots 
or  grains  of  manganese  alloy  that  did  not  melt  and 
mix  properly  with  the  iron.  In  such  cases  more  harm 
is  done  than  good.  A  study  of  the  tests  shows  that 
the  best  results  for  strength  were  dependent  upon  cer- 
tain percentages  of  increase.  Anything  above  or  below 
this  was  injurious.  The  increase  of  manganese  in  the 
molten  metal  ranged  from  25  to  60  per  cent.  The 
effect  of  adding  manganese  to  molten  metal  on  the 
other  elements  shows  an  increase  in  the  silicon  and 
decrease  in  the  sulphur,  with  phosphorus  remaining 
fairly  constant.  With  the  manganese  in  the  cupola, 
the  silicon,  sulphur,  and  phosphorus  are  decreased. 
The  complete  Table  36  of  analyses  affords  one  excellent 
material  for  study  and  information  on  these  points. 

One  peculiarity  noticed,  in  making  these  tests,  was 
seen  in  the  high  manganese  of  tests  Nos.  2  and  6  caus- 
ing the  sand  to  peel  most  freely  from  the  castings  and 
leaving  a  skin  covered  with  flakes  of  graphite,  whereas, 
with  the  same  iron  free  from  the  ferro-manganese 
mixture  the  sand  stuck  strongly  to  the  casting.  All 
the  bars  poured  with  the  iron  having  manganese  added 
in  the  cupola  showed  this  effect  to  a  greater  or  less 
degree.  No  doubt  this  is  the  cause  of  some  castings 


EFFECTS    OF    VARIATIONS- IN    MANGANESE.  245 

made  of  the  same  pattern  peeling  much  more  readily 
than  others,  with  the  use  of  the  same  grades  of  sand 
or  facing  and  equal,  fluidity  of  metal,  a  phenomenon 
many  have  often  been  at  a  loss  to  understand.  In 
regard  to  differences  noticeable  in  the  fluidity  of  the 
metal,  there  was  little  if  any  to  be  seen  between  the 
iron  coming  from  either  side  of  the  cupola,  but  the 
addition  of  manganese  to  the  molten  metal  in  the  ladle 
noticeably  increased  the  fluidity. 

Where  founders  desire  a  ••  white  iron  "  of  the  best 
strength  obtainable  in  castings,  heats  Nos.  8  and  9 
would  show  that  it  can  be  readily  obtained  by  mixing 
ferro-manganese  with* good  strong  grades  of  low  silicon 
pig  or  scrap  iron.  Of  course,  white  iron  can  be 
obtained  with  the  cheapest  grades  of  old  scrap,  but 
this  will  be  much  weaker  than  when  good  iron  and 
ferro-manganese  are  used.  The  amount  of  manganese 
seen  in  heats  Nos.  8  and  9,  with  the  low  silicon  iron, 
is  sufficient  to  make  a  casting  having  a  section  from 
three  to  five  inches  thick  all  white,  when  cast  without 
the  use  of  chill.  Where  sections  are  heavier  a  greater 
percentage  of  manganese  will  be  required.  It  will 
appear  rather  strange  to  many  to  note  the  high  silicon 
charcoal  iron  used  in  heat  No.  3,  as  it  is  rare  that  such 
brands  of  iron  exceed  2.00  per  cent,  in  silicon.  This 
iron  was  obtained  from  the  Jefferson  Iron  Co.,  Jeffer- 
son, Texas.  The  charcoal  iron  in  heats  Nos.  7  and  9 
was  kindly  donated  by  the  Seaman-Sleeth  Co.,  Pitts- 
burg,  Pa.  Further  information  on  the  effects  of  man- 
ganese is  found  on  pages  213  to  215. 


CHAPTER  XXXIII. 

EFFECT  OF  VARIATIONS  IN  TOTAL 
CARBON  IN  IRON. 

By  utilizing  the  twin  shaft  cupola  shown  on  page 
241,  the  author  has  made  comparative  tests  in  several 
different  ways,  in  an  effort  to  discover  the  effect  of 
changes  in  the  total  carbon  in  iron,  all  other  elements 
being  held  fairly  constant.  This  is  a  most  difficult 
factor  to  determine,  owing  to  the  difficulty  of  adding 
carbon  to  iron  as  can  be  done  with  silicon  and  man- 
ganese. The  author  can  now  only  present  opinions 
founded  on  what  might  be  called  indirect  tests.  These 
tests,  in  brief,  lead  the  author  to  say  that  an  increase 
in  the  total  carbon,  with  all  other  elements  remaining 
fairly  constant,  increases  the  life  or  heat  of  molten 
metal,  softens  the  iron,  increases  deflection  and 
decreases  its  strength.  Where  high  carbon  exists 
it  may  cause  a  kish  or  scum  to  rise,  which  may  often 
be  the  means  of  producing  dirty  or  porous  castings. 
Such  results  can  often  be  remedied  by  lowering  the 
carbon  in  mixtures,  by  the  addition  of  low  carbon  pig 
metal  or  steels,  etc. 

It  has  been  suggested  that  more  interest  should  be 
taken  in  utilizing  the  changes  in  the  percentages  of  car- 
bon to  effect  changes  in  the  grade  of  an  iron,  than  in 
variations  of  silicon,  as  commonly  practiced.  This  is 
an  impractical  proposition,  for  the  reason  that  changes 


EFFECT    OF    VARIATIONS    IN    TOTAL    CARBON. 

in  the  percentages  of  carbon  in  iron  cannot  be  controlled 
sufficiently  to  regulate  mixtures  in  everyday  founding. 
This  proposition  is  largely  due  to  some  advocating  that 
the  creation  of  the  graphitic  carbon  is  not  regulated  by 
silicon,  but  due  chiefly  to  changes  in  the  percentages  of 
carbon.  It  is  true  that  the  higher  the  carbon,  the  more 
graphite  there  is  in  normally  made  and  cooled  pig  iron  or 
castings,  other  conditions  being  equal.  Nevertheless, 
variations  in  the  silicon  and  sulphur,  especially  the 
silicon,  are  chiefly  responsible  for  variations  in  the 
graphite  of  different  pig  or  castings.  If  those  who 
think  otherwise  will  take  note  of  variations  in  the  total 
carbon  and  the  combined  carbon  they  will  find  that, 
allowing  for  changes  in  the  percentage  of  total  carbon, 
the  combined  carbon  varies  closely  with  those  of  silicon 
and  sulphur,  especially  the  former ;  or,  in  other  words, 
with  a  constant  total  carbon,  sulphur,  and  manganese, 
etc.,  the  higher  the  silicon,  the  lower  the  combined 
carbon  and  the  higher  the  graphite,  in  normally  made 
and  cooled  pig  iron  or  castings. 

rialleable  founders  notice  that  the  heat  of  iron  is 
to  some  extent  dependent  upon  the  carbon  in  it.  'As  a 
rule  the  low  silicon  irons  give  them  the  highest  carbon. 
When  the  exception  to  this  rule  takes  place  and  they 
get  low  carbon  in  low  silicon  irons,  which  many  prefer, 
they  notice  its  heat  effect  in  a  very  pronounced  manner. 
Iron  with  less  than  i  per  cent,  silicon  may  have  carbon 
up  to  4. 50  per  cent,  while  over  4.00  per  cent,  silicon 
iron  may  often  not  exceed  2.00  per  cent,  carbon. 

To  insure  good  fluidity  it  is  not  to  be  understood, 
by  the  above,  that  it  is  necessary  to  have  carbon  above 
3.75.  To  obtain  good  fluidity,  extra  silicon,  phos- 
phorus, and  often  manganese  are  necessary  to  be  com- 


248  METALLURGY    OF    CAST    IRON. 

bined  with  the  carbon.  It  is  by  a  proper  combination 
of  these  four  elements  that  the  best  fluidity  and  life  in 
molten  metal  is  obtained.  Very  high  carbon  or  silicon 
can  cause  metal  to  be  sluggish  or  thick  on  the  surface, 
at  either  the  furnace  or  foundry.  Such  iron  can  often 
be  seen  evolving  a  great  deal  of  kish  at  the  furnace,  or 
a  scum  at  the  foundry,  and  makes  it  very  difficult,  when 
in  iron,  to  obtain  clean  castings. 

To  obtain  a  thin  or  clean  iron  and  one  which  will  run 
quickly  while  it  is  hot,  in  making  gray  castings,  use 
a  mixture  which  will  give  castings  having  carbon  3.00 
to  3.75,  phosphorus  .80  to  i.oo,  maganese  .40  to  .60, 
silicon  2.50  to  3.00;  sulphur  to  be  below  .07.  Such 
an  iron,  while  running  thin  as  long  as  it  retains  its 
heat,  could  be  made  softer  and  have  longer  life  by 
increasing  the  carbon  and  silicon  above  the  limits  here 
shown,  but  by  doing  this  the  thinness,  or  quicksilver 
action,  would  be  reduced  unless  phosphorus  was 
increased,  which  would  be  liable  to  make  the  castings 
brittle.  The  higher  the  total  carbon,  the  less  silicon. is 
required  to  maintain  the  grade  and  the  higher  can  the 
carbon  be  held  in  a  combined  or  graphitic  state,  other 
conditions  being  equal.  See  pages  280,  282. 


CHAPTER  XXXIV. 

EVILS  OF  EXCESSIVE  IMPURITIES  IN 
IRON. 

As  a  rule  cast  iron  contains  92  to  96  per  cent,  of 
metallic  iron,  the  balance  being  impurities  such  as 
carbon,  silicon,  sulphur,  manganese,  and  phosphorus. 
While  these  latter  five  elements  are  essential  in  iron, 
an  excess  of  their  total  percentages  exceeding  6  per 
cent,  of  cast  iron  is  generally  injurious  to  the  best 
strength.  To  illustrate  how  an  excess  of  the  above 
impurities  can  weaken  iron,  the  following  Table  37  is 
presented.  The  percentage  of  impurities  and  iron 
shown,  also  the  strength  tests,  are  obtained  from  the 
results  seen  in  Tables  108  to  114,  pages  536  and  537. 
By  a  study  of  the  following  Table  37,  one  should  per- 
ceive that  changes  in  the  total  percentages  of  the 
carbon,  silicon,  sulphur,  manganese,  and  phosphorus 
can  have  quite  an  influence  on  the  strength  of  castings. 
For  example,  the  chilled  roll  mixture  (Table  37) 
possessing  only  4.803  impurities,  as  against  6.218  in 
the  Bessemer  mixture,  with  others  between  them 
showing  a  uniform  decrease  in  strength,  demonstrate 
that  if  the  impurities  exceed  6  per  cent,  of  the  total  the 
iron  generally  decreases  in  strength  according  to  the 
increase  of  impurities.  One  is  not  to  be  wholly  guided 
by  the  results  presented  in  Table  37,  as  any  one  can 
figure  other  tests,  wherever  found,  and  test  the  prin- 
ciples here  set  forth. 


250 


METALLURGY    OF    CAST    IRON. 


TABLE   37 PERCENTAGES     OF    IRON     AND     IMPURITIES    IN    WEAK     AND 

STRONG    CASTINGS. — SEEN    ON    PAGES    536   AND    537. 


Chill 
Roll. 

Gun 
Metal. 

Car 
Wheel. 

General 
Machin- 
ery. 

Stove 
Plate. 

Bessemer 
Iron. 

Iron  

95  -*97 

95.120 

94.088 

94.100 

92.473 

93.782 

Impurities.  

4-803 

4.880 

5-012 

5.900 

7-527 

6.218 

Total  

100.00 

100.00 

100.00 

IOO.OO 

100.00 

IOO.OO 

Strength  of  largest 
bar 

5,013 

4,355 

4,263 

3,786 

3,  on 

2  860 

Relative  strength... 

100. 

87. 

85. 

75- 

60. 

57- 

Relative  estimated 
strength  

100. 

86. 

84. 

77. 

81-5 

68. 

Impurities  in  charcoal  pig  iron  are  less,  as  a  rule, 
than  in  coke  or  anthracite  pig  iron.  This  causes  the 
"  iron  "  to  be  higher  in  the  former  metal.  It  is  now 
conceded  that  this  is  a  great  cause  for  charcoal  irons 
excelling  coke  or  anthracite  pig  metal  in  making  strong 
castings,  when  intelligently  used.  The  advantages  of 
having  high  ' '  iron  ' '  in  castings  requiring  strength  are 
illustrated  in  steel  metal.  This  was  ably  set  forth  in 
a  paper  treating  of  the  importance  of  having  high 
"  iron  "  in  cast  pig  metal  by  the  late  Captain  Henning 
of  the  Imperial  Artillery,  Berlin,  Germany,  before  the 
local  foundrymen's  association,  February  5,  1901, 
wherein  he  stated  that  steel  castings  show  only  .074  to 
1.44  per  cent,  of  impurities  and  98.56  to  99.86  per 
cent.  iron. 

The  results  of  the  computation  of  iron  as  shown  in 
Table  37  were  first  given  by  Mr.  Whitney  in  a  discus- 
sion of  a  paper  by  the  author  seen  in  Chapter  LXIX. 
before  the  Foundrymen's  association,  Philadelphia, 
December  2,  1896.  During  the  above  discussion  Mr. 


EVILS    OF    EXCESSIVE    IMPURITIES    IN    IRON.  251 

Whitney  dwelt  at  considerable  length  upon  the  practi- 
cability of  estimating  the  strength  of  iron  or  castings  by 
analyses,  and  was  of  the  conviction  that  the  day  was 
not  far  distant  when  such  would  be  generally  accepted 
as  being  practical.  How  closely  Mr.  Whitney  esti- 
mated the  strength  by  analysis  is  shown  by  the  relative 
estimated  strength  in  Table  37. 

The  general  method  of  estimating  the  iron  in  cast 
metal  is  by  deducting  the  total  of  the  silicon,  sulphur, 
manganese,  phosphorus,  and  carbon  percentages  from 
100.00.  If  there  have  been  any  errors  in  figuring 
these  various  percentages  they  would,  by  the  above 
calculating  process,  be  then  thrown  all  on  to  the  iron, 
so  that  as  a  check  to  positively  determine  the  iron  in 
metal  it  is  really  necessary  to  weigh  up  the  iron  after 
the  other  elements  are  taken  away  from  it,  when 
making  the  analyses,  or  make  an  analysis  of  the  iron 
only  and  then  let  such  be  recorded  in  a  column  adjoin- 
ing that  of  the  totals  for  the  carbons.  Of  course, 
wherever  the  ' '  iron  ' '  is  not  shown  in  analyses  it  can, 
by  the  above  plan,  be  estimated  as  far  as  such  is  to  be 
valued  and  thus  be  made  to  serve  for  obtaining  the 
' '  iron  ' '  contained  in  any  tests. 


CHAPTER  XXXV. 

CHARACTER  OF  SPECIALTIES  MADE  OF 
CAST  IRON. 

The  following  table,  No.  38,  will  afford  a  fair  idea  of 
the  character  of  specialties  now  being  made  of  cast 
iron: 

TABLE    38. 


1.  Toys  and  statuary.  21. 

2.  I^ocks  and  hinges.  22. 

3.  Stoves  and  heating  furnaces.  23. 

4.  Hollow  ware.  24. 

5.  Bath  tubs.  25. 

6.  Furniture  castings.  26. 

7.  Piano  plates.  27. 

8.  Dynamos  and  Electrical  Work.  28. 

9.  Small  pipe  fitting  and  valves.  29. 

10.  Radiators.  30. 

11.  Pulleys.  31. 

12.  Wood-working  machinery.  32. 

13.  Weaving  machinery.  33. 

14.  Farming  implements.  34. 

15.  Molding  machines  for  founding.  35. 

16.  Fans  and  blowers.  36. 

17.  Printing  presses.  37. 

18.  Journal  boxes,  shaft  hangers.  38. 

19.  lathes,  planers,  machine  tools.  39. 

20.  Street  lamps  and  hitching  posts.  40. 


Water  and  gas  pipes. 

Sidewalk  grating  and  manholes. 

Furnace  and  floor  plate  castings. 

Sash  weights. 

Architectural  castings. 

Pneumatic  hoists  and  machinery. 

Gas  engines. 

Ammonia  freezing  machinery. 

Air  brakes  and  railway  castings. 

Steam  and  water  pumps. 

Hydraulic  cylinders  and  machines. 

Steam  and  blowing  engines. 

Hand  and  machine  molded  gears. 

Mining  machinery. 

Punch,  shears  and  dies. 

Ingot  molds  and  stools. 

Annealing  pots  and  pans. 

Cannon,  shot  and  shell. 

Chilled  car  wheels. 

Sand  and  chilled  cast  rolls. 


Aside  from  the  above  classifications,  there  is  a  great 
variety  of  light  and  heavy  castings  used  in  different 
forms  in  the  miscellaneous  construction  and  use  of 
castings.  The  list  gives  us  about  forty  specialties, 


CHARACTER    OF    SPECIALTIES    MADE  OF    CAST    IRON.     253 

many  of  which  call  for  different  grades  or  mixtures  of 
iron  and  some  of  which  differ  very  radically.  Those 
ranging  from  Nos.  i  to  9  generally  call  for  variations 
in  what  is  known  as  the  softest  grades  of  iron.  Those 
ranging  from  Nos.  10  to  22  generally  require  variations 
in  the  medium  soft  grades  of  iron.  No.  23  can  gener- 
ally be  made  of  harder  iron  than  permissible  in  the 
numbers  above  it.  No.  24  is  generally  made  of  the 
poorest  refuse  of  iron,  consisting  often  of  old  rusty 
stove  plate,  burnt  grate  bars,  and  annealing  pots,  also 
tin  sheet  scrap  iron.  A  mixture  of  these  inferior 
grades  generally  gives  a  hard  white,  or  very  brittle 
grade  of  metal.  Nos.  25  to  29  are  a  class  of  castings 
that  will  generally  require  a  different  mixture  and  a 
harder  iron  than  those  ranging  from  Nos.  10  to  22. 
Nos.  30  to  35  are  specialties  which  generally  call  for  as 
strong  grades  of  iron  as  can  be  finished  in  lathes, 
planers,  etc.  Strong  grades  of  iron  can  be  made  so 
hard  as  to  make  it  difficult  to  turn  or  plane  them  in 
finishing  such  castings.  Charcoal  iron  is  often  largely 
used  in  these  latter  grades,  whereas,  in  Nos.  i  to  29  it 
is  rare  that  such  is  used,  as  coke  iron  can  generally  be 
made  to  answer  all  purposes.  Nos.  36  and  37  require 
a  grade  of  iron  very  distinct  from  the  other  specialties 
shown,  owing  to  such  castings  having  to  stand  radical 
changes  of  temperatures,  which  cause  an  action  of 
alternate  expansion  and  contraction  while  the  castings 
are  in  use.  Iron  of  a  medium  soft  character  and  low 
in  phosphorus,  or  what  is  termed  regular  Bessemer,  is 
found  best  for  such  castings.  The  cannon  of  No.  38 
calls  for  a  grade  of  iron  that  should  be  of  fair  ductility, 
but  at  the  same  time  possess  the  greatest  strength  to 
be  obtained.  Cannons  are  generally  made  from  the 


254  METALLURGY    OF    CAST    IRON. 

best  brands  of  charcoal  iron  melted  in  an  air  furnace, 
which  is  superior  to  a  cupola  in  giving  the  best  grades 
of  iron  for  such  castings.  Nos.  39  and  40  are  made  of 
what  are  called  chilling  irons,  and  which  may  be  com- 
posed of  a  mixture  of  charcoal  and  coke  irons,  or  of  all 
charcoal  iron.  The  rolls  are  best  made  of  iron  melted 
in  an  air  furnace,  although  many  are  cast  with  iron 
melted  in  a  cupola.  Chilling  irons  differ  most  radi- 
cally from  the  grades  or  brands  generally  used  in  the 
specialties  Nos.  i  to  38.  For  information  on  making 
mixtures  for  specialties  herein  described,  see  Chapters 
XXXVI.  to  XLIII.  pages  255  to  292. 


CHAPTER  XXXVI. 

METHODS  FOR  CALCULATING  THE 
ANALYSES  OF  MIXTURES. 

Some  adopting  chemistry  in  making   mixtures  of 

iron  have  the  impression  that  iron  should  come 
from  the  furnaceman  to  them  possessing  the  exact 
analysis  required  for  charging.  It  is  rare  that  furnace  - 
men  can  do  this.  In  our  practice,  although  surrounded 
by  blast  furnaces  from  which  we  may  obtain  iron,  we 
are  often  compelled  to  accept  two  or  more  different 
grades  of  extreme  variations  of  silicon,  etc.,  in  order 
to  make  a  mixture  desired.  As  a  rule,  two  or  three 
different  grades  will  often  have  to  be  accepted,  espe- 
cially by  those  using  a  large  amount  of  iron,  in  order  to 
obtain  the  average  which  should  be  charged.  (See 
Chapter  XXL,  page  155.) 

To  illustrate  methods  that  will  utilize  iron  of  differ- 
ent grades  as  used  by  the  author  and  others,  we  will 
suppose  that  a  charge  of  2,000  pounds  having  an  aver- 
age composition  as  shown  in  Tables  39  and  40  is 
desired.  These  tables  show  that  by  a  mixture  of  three 
different  grades  of  iron  and  two  of  scrap,  an  average 
of  2.00  silicon,  .032  sulphur,  .62  manganese,  .435  phos- 
phorus, and  3.80  carbon,  as  shown  in  Table  41,  is 
obtained  in  the  iron  to  be  charged  into  the  cupola 
Another  plan  is  to  divide  the  weight  of  each  kind  of  iron 
into  percentages,  after  the  method  seen  in  Table  42. 


256 


METALLURGY    OF    CAST    IRON. 
TABLE    39  —  CALCULATING    THE    SILICON. 


Brand  and  Grade  of 
Iron  Used. 

Weight  of  Iron 
Used. 

Percentage 
Silicon. 

Total  Points  of 
Silicon. 

No.  i  Flora 

600  Ibs          x 

2  80                «= 

1680  oo 

No.  3  Clara  

400  Ibs.         x 

2  26                — 

No.  6  Frank 

300  Ibs.          x 

I  50                — 

Shop  scrap  

200  Ibs.          x 

1.  80                — 

Yard  scrap         

500  Ibs.          x 

I  25                — 

2,000  Ibs. 


4019.00 


TABLE   40  —  PERCENTAGES   OF    SULPHUR,   MANGANESE,   PHOSPHORUS  AND 
CARBON    IN    THE    DIFFERENT    IRONS. 


Brand  and 
Grade  of 
Iron  Used. 

Weight  of 
Iron  Used. 

Sulphur. 

Man- 
ganese. 

Phos- 
phorus. 

T.  Carbon. 

No.  i  Flora... 

600  Ibs. 

.01 

.60 

•3° 

3-50 

No.  3  Clara... 

400  Ibs. 

.01 

.70 

.40 

3-7« 

No.  6  Frank. 

300  Ibs. 

•03 

.80 

•5° 

3-90 

Shop  scrap... 

200  Ibs. 

•05 

.60 

.40 

4.00 

Yard  scrap... 

500  Ibs. 

.07 

•50 

.60 

4.10 

TABLE    41  —  RESULTS    OF    COMPUTATION    OF   TABLES    39    AND    40. 


4019.00  pts.  silicon  -:-   2,000  Ibs. 

64.00  pts.  sulphur  -:-  2.000  Ibs. 
1250.00  pts.  manganese  -:-  2,000  Ibs. 

87.00  pts.  phosphorus  -:-  2,000  Ibs. 
38400.00  pts.  carbon  -:-  2,000  Ibs. 


2.00    per  cent  silicon. 
.032        "          sulphur. 
.62          "          manganese. 


.435 
3.80 


phosphorus. 
carbon. 


TABLE    42  —  METHOD    OF    CHECKING    TABLE    39. 


Brand  and  Grade 
of  Iron  Used. 

Per  cent  of  Iron 
Used. 

Per  cent  of 
Silicons. 

Total  per  cent  of 
Silicon  in  100 
Parts. 

No.  i  Flora  

30            x 

2.80            = 

84.00 

No.  3  Clara  
No.  6  Frank  
Shop  scrap  
Yard  Scrap  

20                 X 

15            x 

10                 X 

25            x 

2.26            = 

1.50 
i.  80 
1.25 

45-20 
22.50 
18.00 
31.25 

100  parts 

- 

200.95 

One  part  equals  about  2.00  per  cent  of  silicon. 


CALCULATING    ANALYSES    OF    MIXTURES.  257 

The  total  of  i. oo  parts  giving  us  200.95  °f  silicon, 
one  part  will  equal  about  2.00  per  cent,  of  silicon,  the 
same  as  obtained  by  the  methods  shown  in  Table  39, 
and  shows  one  method  to  be  an  excellent  check  for  the 
other.  It  is  true  Table  39  only  deals  with  the  silicon, 
but  it  can  be  seen  by  Table  41  that  its  principles  will 
also  hold  good  for  figuring  the  percentages  of  any  of 
the  metalloids.  It  will  be  noticed  that  in  obtaining 
the  average  percentages  of  the  silicon,  manganese,  and 
carbon  they  are  figured  to  the  second  decimal,  and  the 
sulphur  and  phosphorus  to  the  third. 

The  grade  of  scrap  iron  used  is  judged  by  the  appear- 
ance of  its  fracture  after  the  plan  described  in  Chapter 
XLIL,  and  the  change  which  takes  place  in  remelting 
the  iron  to  reduce  the  silicon  and  manganese  and 
increase  the  sulphur  and  phosphorus  of  the  mixture 
charged  is  described  in  Chapter  XLIV.  This  change 
is  such  that,  with  a  mixture  as  per  Table  41  and  charged 
into  a  cupola,  the  resulting  castings  would  contain 
about  1.70  to  i. 80  silicon,  .05  to  .06  sulphur,  .45  to  .55 
manganese,  .48  to  .55  phosphorus,  and  3.75  to  3.90 
total  carbon. 

While  for  definite  calculations  Tables  39  to  42  afe 
presented,  there  are  cases  where  one  may  utilize 
different  percentages  of  silicon,  sulphur,  etc.,  by 
mere  mental  calculation,  after  the  ideas  seen  on 
page  141,  that  may  answer  all  practical  purposes. 
While  the  rules  of  Tables  39  to  42  may  appear,  at 
first,  complicated,  to  those  unaccustomed  to  such 
computations,  they  would,  with  a  little  practice,  soon 
find  the  methods  very  simple. 


CHAPTER  XXXVII. 

CONSTRUCTION    OF    CHEMICAL    FORMU- 
LAS  AND  EFFECT   OF  PHYSICAL 
ELEMENTS   IN    CASTING 
CHILLED  WORK. 

Chemistry  has  proved  of  greater  benefit  in  making 
mixtures  for  chilled  castings  than  in  any  other  line. 
When  the  progressive  founder  thinks  back  to  the  days 
when  the  chill  roll,  car  wheel,  and  other  manufacturers 
were  guided  wholly  by  judgment  of  fracture  in  select- 
ing their  pig  metal  to  make  a  mixture,  he  is  not  at  a  loss 
to  comprehend  why  such  bad  results  in  castings  were 
then  obtained,  accompanied  by  heavy  financial  losses. 

In  making  grey  iron  castings,  there  is  a  much 
greater  margin  for  a  divergency  from  the  best  point 
to  be  reached  as  regards  the  "  grade  "  desired  than 
with  chilled  work.  In  many  cases  where  soft  work  is 
wanted  it  may  be  found  very  hard  and  still  be  passed, 
or  do  no  injury  other  than  cause  extra  labor  in  finish- 
ing the  castings,  etc. ;  but  as  a  general  thing  if  chilled 
mixtures  diverge  much  from  the  best  point  to  be  at- 
tained, the  castings  will  prove  worthless  by  reason  of 
44  chill  cracks  "  or  the  4<  chill  "  not  be  of  the  depth  or 
quality  of  hardness  desired.  It  is  true  that  most 
chilled  work  founders  would  take  "chill  tests "  of 
their  mixture  after  they  had  melted  their  irons.  This 


PHYSICAL    ELEMENTS    IN    CHILLING    CASTINGS.  259 

would  to  a  great  extent  be  a  guide  for  their  next  *  *  heat, '  * 
providing  the  pig  metal  to  be  used  was  exactly  the 
same.  In  melting  iron  in  an  "  air  furnace  ' '  there  is  a 
chance  to  change  its  composition  from  what  a  "  chill 
test ' '  might  prove  it,  before  the  metal  would  be  tapped 
or  poured  into  a  mould ;  but  with  cupola  work  such  a 
practice  is  not  permissible.  Small  cupolas  may,  in  some 
cases,  be  used  to  test  pig  metal  before  it  is  used  in  regular 
cupola  mixtures,  but  analyses  are  generally  a  cleaner  and 
preferable  plan.  It  is  only  where  analyses  cannot  be 
obtained  or  relied  on  that  testing  pig  metal  in  small 
cupolas,  before  being  used  in  regular  mixture,  is  a  plan 
which  it  may,  in  some  cases,  be  well  to  adopt. 

The  above  treatment  of  this  subject  is  not  to  be 
taken  as  decrying  the  plan  of  taking  ' '  chill  tests  ' '  of 
mixture  in  any  or  all  cases,  as  such  course  is  advisable 
under  all  circumstances,  since  it  enables  a  founder 
having  experience  to  form  a  close  estimate  of  what  he 
has  obtained  in  his  castings  and  assists  him  to  know 
whether  a  change  in  the  chemical  properties  would  be 
advisable  for  any  following  heats.  Chilled  work  will 
always  crystallize  in  planes  at  right  angles  to  the  chill- 
ing surface  of  the  iron  mould  used  for  chilling  the  cast- 
ing. A  standard  chill  which  the  author  has  devised  for 
testing  the  "chill "of  iron  can  be  seen  in  Chapter  LXIX. 

The  factors  most  constant  in  testing  the  chill  of 
an  iron  are  heat  and  friction.  Heat  is  the  best  factor 
for  testing  the  durability  of  such  castings  as  rolls,  and 
friction  those  like  car  wheels.  It  is  not  to  be  taken 
for  granted,  as  held  by  many,  that  "  white  "  or  chilled 
iron  has  no  degree  of  hardness  or  that  the  depth  of  a 
chill  determines  the  hardness,  for  this  is  not  true. 
We  may  have  two  castings  of  exactly  the  same  depth 


260  METALLURGY    OF    CAST    IRON. 

of  a  chill  or  that  maybe  wholly  "  white  iron  "  and  still 
find  a  difference  in  the  hardness  of  iron.  A  good  arti- 
cle on  testing  hardness,  etc. ,  appears  on  page  434. 

The  success  of  chilled  work  is  as  dependent  upon  the 
degree  of  hardness  of  the  chill  as  upon  its  depth.  One 
set  of  conditions  may  exact  a  harder  chill  than  another, 
and  what  may  prove  best  in  one  line  of  work  may  be 
a  failure  in  another ;  as,  for  example,  the  same  kind 
of  chill  would  not  answer  as  well  for  paper  or  calender 
purposes  as  for  steel  or  iron  rolling.  Variations  in  sul- 
phur, manganese  and  phosphorus  are  chiefly  potential 
in  giving  a  special  character  to  the  hardness  of  a  chill. 

For  "  friction  wear,"  as  with  car  wheel,  high  sul- 
phur will  give  better  life  than  high  manganese  com- 
bined with  low  silicon,  to  cause  chill.  For  "heat  wear, ' ' 
hardness  or  chill  is  best  obtained  by  high  manganese 
in  preference  to  sulphur  combined  with  low  silicon. 
Chilled  iron  is  rarely,  in  any  case,  a  homogeneous  mass, 
and  sulphur,  more  than  any  other  element,  retards  the 
union  of  the  molecules  to  best  attain  tenacity  in  the  life 
and  wear  of  iron  subjected  to  heat.  While  it  is  true 
that  we  find  in  present  practice  that  hardness  is  gener- 
ally obtained  by  the  higher  sulphur,  as  can  be  seen  from 
many  of  the  analyses  shown  herein,  and  others  recorded, 
still  wherever  manganese  can  be  applied  in  preference 
to  sulphur,  to  affect  the  carbon,  in  giving  hardness  to 
chill  rolls,  etc.,  better  results  in  preventing  surface 
cracks,  etc. ,  may  be  expected.  A  chill  which  is  chiefly 
promoted  by  manganese  will  prove  more  yielding  to 
strains  and  not  so  liable  to  chill-crack  from  heat  as 
a  chill  which  has  been  chiefly  promoted  by  sulphur. 

Then  again,  manganese  causes  a  more  gradual  de- 
cline from  the  white  to  the  grey  in  chilled  castings 


PHYSICAL    ELEMENTS    IN    CHILLING    CASTINGS.          261 

than  does  sulphur.  It  is  claimed  that  this  same  effect 
is  caused  by  the  use  of  low  phosphorus  iron,  and  is  so 
radical  that  it  makes  the  interlacing  of  the  grey  and 
chilled  bodies  very  pronounced,  as  shown  in  Fig.  57, 
page  264.  In  referring  again  to  manganese,  it  can  be 
said  that  its  effect  to  harden  is  often  partly  neutralized 
by  the  sulphur  it  expels,  hence  its  power  to  increase 
hardness  may  sometimes  be  very  small  and  often  call 
for  a  large  increase  of  manganese  before  it  can  produce 
any  pronounced  effect. 

Professor  Ledebur's  division  of  carbon  into  four 
states,  wherein  he  describes  the  elements  (as  seen  in 
Table  44,  page  267)  existing  in  carbon  as  hardening, 
carbide,  graphitic,  and  temper-carbon,  is  a  factor  that 
some  believe  may  account,  in  some  cases,  for  like 
depths  of  chill  not  presenting  like  degrees  of  hardness, 
also  to  account  for  other  qualities  in  physical  effects 
which  at  present  are  not  clearly  defined.  The  pro- 
fessor treated  this  subject  in  a  paper  before  the 
Iron  and  Steel  Institute,  found  in  their  Proceedings, 
No.  2,  1893.  Some  are  of  the  opinion  that  the  differ- 
ences seen  in  the  grain  of  charcoal  from  coke  iron, 
although  the  former  may  carry  higher  graphitic 
carbon,  is  due  to  there  being  a  relatively  larger  per 
cent,  of  graphitic  temper-carbon  in  charcoal  than  in 
coke  iron,  which  is  formed  while  the  carbon  is  in  a 
transition  state  toward  graphite.  It  is  unfortunate, 
as  stated  by  Professor  Ledebur,  that  there  is  no  known 
method  of  analyzing  graphitic  temper-carbon,  or 
that  it  can  only  be  determined  by  being  estimated 
with  the  graphite.  If  this  could  be  determined  there 
would  be  much  more  interest  taken  to  note  its  effect 
in  castings. 


262  METALLURGY    OF    CAST    IRON. 

In  making  chilled  work,  it  is  essential  to  understand 
the  various  effects  which  the  different  metalloids  have 
in  controlling  the  combined  carbon,  associated  with  a 
knowledge  of  the  individual  effect  of  each  metalloid 
in  regulating  the  character  of  the  hardness  best  calcu- 
lated to  stand  the  wear  of  friction  or  heat,  as  outlined 
in  the  former  part  of  this  Chapter. 

In  a  general  way  it  can  be  said  that  the  percentage 
of  the  chemical  constituents  which  combine  to  make 
chill  castings  ranges  in  silicon  from  0.50  to  i.io,  man- 
ganese from  0.55  to  1.50  per  cent.,  phosphorus  from 
0.20  to  0.70  and  in  sulphur  from  .02  to  .10,  with  the 
total  carbon  from  2.50  to  3.75. 

The  quality  to  be  first  understood  is  the  depth  of  the 
chill  and  hardness  desired  in  a  casting;  second,  the 
chilling  properties  of  the  iron  to  be  used.  To  make  a 
comparative  test  in  order  to  learn  of  the  chilling  quali- 
ties of  an  iron  by  casting  chill  specimens,  it  should  be 
remembered  that  '*  *  hot  iron  ' '  will  chill  deeper  than 
'*  dull  iron,"  and  that  note  should  be  taken  of  the 
same,  in  connection  with  the  other  elements  of  chill- 
ing, as  outlined  in  Chapter  LVI.  It  is  also  to  be  re- 
membered that  manganese  will  give  longer  life  to  the 
fluidity  of  metal  than  sulphur,  where  preference  can 
be  given  either,  in  producing  the  combined  carbon. 
It  is  very  important  in  assisting  to  prevent  "  cold 
shuts"  or  "  chill  cracks,"  when  pouring  a  mould,  to 
have  the  metal'  run  freely,  and  hence  the  advantage 
of  manganese  over  sulphur,  as  above  stated.* 

*  Information  on  the  thickness  of  chills,  methods  for  making 
and  pouring  "chilled"  castings,  also  making  clean  and  smooth 
and  perfect  work,  can  be  found  on  pages  272  and  276  in  "Amer- 
ican Foundry  Practice,"  and  page  234  in  "Moulder's  Text-Book." 


CHAPTER  XXXVIII. 

MIXTURES    FOR    CHILLED    ROLLS,    CAR 
WHEELS,   ETC. 

The  use  of  chilled  castings  has  grown  to  such  an 
extent  that  we  find  the  following  chilled  specialties 
being  manufactured:  Rolls  for  various  purposes,  car 
wheels,  crushers  for  breaking  ore,  etc. ,  squeezers  for 
balling  iron,  die  presses,  anvils,  armor  for  inland 
fortification,  shot  and  shell,  axle  bearings,  grinding 
and  grist  machinery,  switches  for  railroads,  turn-tables 
and  transfer  plates,  boiling  pans  for  various  chemical 
purposes,  cutting  tools,  plows,  and  numerous  other 
specialties  that  might  be  mentioned  to  illustrate  the 
extent  to  which  the  manufacture  of  chilled  castings 
is  used. 

In  making  mixtures  for  chilled  rolls,  it  is  generally 
necessary  to  consider  the  thickness  through  the  nepk 
and  body  of  the  rolls,  the  thickness  of  chill  desired 
in  the  castings,  and  whether  they  are  to  be  used  for 
cold  or  hot  rolling;  also  the  thickness  of  the  chill 
mould  used  and  the  temperature  of  the  metal  in  pour- 
ing, as  seen  by  Chapters  LI.  and  LVI.  The  thickness 
of  chill  is,  in  some  cases,  desired  from  ^  to  ^  inch, 
and  then  again  from  ^  to  i  inch.  It  is  rare  that  more 
than  i  y±  inches  thickness  of  chill  is  desired  in  rolls. 
The  founder  is  supposed  to  have  such  a  control  over 
mixtures  that  he  can  attain  to  within  a  inch  of 


264 


METALLURGY    OF    CAST    IRON. 


the  chill  thickness  desired.  Then  again,  some  users 
prefer  a  sharply  defined  chill  joining  the  gray  body, 
While  others  prefer  the  chill  and  gray  body  to  interlace 
or  mingle  with  each  other  when  combined.  This  feat- 
ure is  well  displayed  in  the  chilled  section  of  car  wheel 
seen  at  AB,  Fig.  57,  tendered  the  author  by  the 
Pennsylvania  Car 
Wheel  Co.  of  Pitts- 
burg,  Pa.  This  factor 
is  further  treated  in 
Chapter  XXXVII., 
page  260. 

Chilled  rolls  for  hot 
rolling  require  differ- 
ent qualities  than  those 
used  for  cold  rolling, 
and  are  a  type  of  rolls 
subjected  to  the  great- 
est abuse.  This  abuse 
lies  in  alternate  ex- 
pansion and  contrac- 
tion which  takes  place 
in  the  outer  body  of 
the  rolls,  being  sud- 
denly heated  to  about 
500  degrees  F.  and 
then  cooled  to  the  atmosphere.  The  force  of  this  power 
is  often  noticeable  in  remelting  rolls  in  air  furnaces, 
where  from  sudden  heating  of  the  outer  body  they 
will  crack,  in  two  or  more  pieces,  with  an  explosion 
that  can  often  be  heard  for  quite  a  distance.  Rolls 
for  hot  turning  should  not  only  be  of  such  a  character 
as  to  withstand  the  above  alternate  strains,  but  possess 


FIG.    57. — SECTION    OF    CHILLED    CAST 
IRON   CAR   WHEEL. 


MIXTURES    FOR    CHILL    ROLLS,     CAR    WHEELS,    ETC.      265 

a  solid,  hard  surface  free  of  all  defects,  that  will  not 
spawl  or  shell  off  by  usage,  and  a  depth  of  chill  which 
will  permit  the  face  being  trued  up  occasionally  until 
the  chill  is  nearly  worn  off. 

The  character  of  iron  used  for  chilled  rolls  consists 
largely  of  cold  and  hot  blast  charcoal  iron,  often 
mixed  with  broken  rolls,  car  wheels,  and  sometimes 
steel  scrap.  Cold  blast  charcoal  combines  strength 
with  ductility  more  than  any  other  iron  and  excels  all 
other  brands  for  the  manufacture  of  chilled  rolls.  Char- 
coal iron  of  Salisbury  and  Muirkirk  brands  are 
generally  considered  as  excellent  irons  for  chilled 
rolls,  car  wheels,  etc.  Many  in  making  rolls  will 
use  a  good  deal  of  old  car  wheels  and  steel 
scrap  in  their  mixtures.  For  an  example,  the  author 
has  used  a  mixture  of  1,300  pounds  of  old  car 
wheels  and  300  pounds  of  steel  rail  butts  for  mak- 
ing rolls  about  14  inches  in  diameter  that  required  i^- 
inch  thickness  of  chill.  Wherever  scrap  is  used  in 
mixture  with  pig,  care  must  be  taken  to  have  it  of  as 
uniform  a  grade  as  practical.  Another  mixture  con- 
sisted of  1,000  pounds  of  car  wheel  scrap,  500  pounds 
of  No.  4,  and  500  pounds  of  No.  5  charcoal  iron.  It 
is  to  be  remembered,  wherever  we  refer  to  grade  num- 
bers, that  they  are  supposed  to  contain  silicon  and 
sulphur  agreeing  with  table  22,  page  152;  and  by 
referring  to  the  analysis  of  the  car  wheel  seen  on 
page  268  one  can  perceive  about  what  constituents  the 
above  scrap  should  contain.  For  further  information 
on  adding  steel  scrap  to  iron  mixtures  and  melting  it, 
see  "  Moulder's  Text-Book. "  Some  select  car  or  other 
chilled  scrap  by  the  thickness  of  the  chill,  but  since 
it  has  become  known  that  the  pouring  temperature  can 


266 


METALLURGY    OF    CAST    IRON. 


vary  the  depth  of  a  chill  in  castings,  as  seen  by  Chap- 
ters LI.  and  LVL,  it  is  best  to  be  guided  by  analyses 
of  the  grey  body  of  the  chilled  castings  or  scrap. 

The  impracticability  of  formulating  standard  mix- 
tures will  be  realized  after  a  study  of  the  varying 
conditions  which  must  be  met  in  actual  practice.  Each 
founder  must  formulate  his  own  mixtures,  based  upon 
the  principles  shown  in  this  and  the  preceding  chapter. 
It  may  be  stated  that  mixtures  for  chilled  rolls,  which 
include  any  scrap  used  as  well  as  the  pig,  may  often 
range  in  analysis  when  ready  for  charging  as  per 
Table  43.  The  wide  variations  in  the  sulphur,  man- 
ganese, and  phosphorus  seen  is  given  for  the  purpose 
of  showing  the  range  generally  necessary  to  cause 
the  different  character  of  chills  often  required,  as  seen 
by  a  study  of  the  preceding  chapter. 

TABLE  43 — APPROXIMATE  ANALYSES  FOR  CHILLED  ROLL  MIXTURES. 


Diameter  of 
Rolls. 

Silicon. 

Sulphur. 

Man- 
ganese. 

Phos- 
phorus. 

Total 
Carbon. 

8"  to  10" 

1.  00 

.01  to  .06 

.15  to  1.50 

.20  to  .80 

2.60  to  3.25 

12"  to  14" 

.80 

.01  to  .06 

.15  to  i  50 

.20  tO    .80 

2.60  to  3.25 

16"  to  18" 

.70 

.01  to  .06 

.15  to  1.50 

.20   tO    .80 

2.60  to  3.25 

20"    tO    22" 

.60 

.01  to  .06 

.15  to  1.50 

.20   tO    .80 

2.60  to  3.25 

24"  to  26" 

•50 

.01  to  .06 

.15  to  1.50 

.20  to  .80 

2.60  to  3.25 

To  illustrate  Professor  Ledebur's  division  of  carbon 

in  rolls,  referred  to  in  Chapter  XXXVII.,  page  261, 
Table  44  is  given.  Iron  is  melted  in  both  air  furnaces 
and  cupolas  for  casting  rolls.  The  air  furnace  is  the 
best  for  melting  such  mixtures  as  it  gives  a  purer 
metal,  on  account  of  not  compelling  the  iron  to  be  in 
contact  with  the  fuel  when  being  melted,  as  it  is  in 
cupola  practice.  In  melting  iron  in  air  furnaces  care 
must  be  exercised  to  avoid  an  oxidizing  flame,  as  this 


MIXTURES    FOR    CHILL    ROLLS,     CAR    WHEELS,     ETC.       267 

can  deteriorate  the  metal  and  often  leave  it  no  better 
than  cupola  iron.      For  sand  roll  mixtures,   see  page 

273- 

TABLE   44 — ANALYSIS   OF   TWO    ROLLS   THAT   STOOD    WELL. 
BY  PROF.  A.  LKDBBUR. 


Roll  i. 

Roll  2. 

Hardening1  Carbon    

0.58 

O-4S 

Carbide  Carbon    ..            

2  43 

o  46 

I  Q^ 

Total  Carbon  

3  20 

2  84 

Silicon                    

o  83 

o  80 

Phosphorus         ..       .          

0.88 

0.88 

O  IO 

0  IO 

The  main  difference  between  mixtures  for  chilled  rolls 
and  car  wheels  lies  in  coke  iron  being  used  in  mixture 
with  charcoal  iron  —  or  alone,  for  the  latter  —  and  the 
iron  being  melted  in  a  cupola  instead  of  an  air  furnace. 
A  few  have  used  steel  scrap  in  mixture  with  pig  iron 
for  car  wheels,  but  in  such  cases  great  care  has  to  be 
exercised  to  procure  a  uniform  product  of  steel.  The 
more  general  practice  is  to  depend  upon  pig  iron  that 
has  been  melted  in  a  small  cupola  to  test  it  physically 
as  well  as  chemically  before  it  is  used  in  the  regular 
cupola,  where  it  may  be  mixed  with  old  car  wheels  and 
shop  scrap.  The  following  Table  45,  taken  from  an 
excellent  paper  on  "  The  Manufacture  of  Car  Wheels  " 
by  Mr.  G.  R.  Henderson  before  the  American  Society 
of  Mechanical  Engineers,  Washington,  May,  1899, 
presents  the  analyses  of  seven  wheels  which  had  given 
from  eight  to  eleven  years  of  service.  An  analysis  ot 
a  good  wheel  by  Mr.  A.  Whitney  is  also  given  in 
Table  46. 


268 


METALLURGY    OF    CAST    IRON. 


TABLE  45. 


Graphitic  carbon.... 
Combined  carbon... 

Silicon 

Manganese 

Sulphur 

Phosphorus 


.2.56  per  cent  to  3. 10  per  cent. 
.  .63    "      "      "  i. 01     " 

.  .58    "       "      "     .68    " 
.  .15     "  "     .27     " 

.  .05     "       "      "     .08     " 
.  .25     "  '     .45     " 


TABLE   46 — ANALYSIS  OF  A  REMARKABLY  STRONG  CAR  WHEEL. 
BY  MR.  A.  WHITNEY. 


Combined 
Carbon. 

Graphite. 

Manga- 
nese. 

Silicon. 

Phosphor. 

Sulphur. 

Copper. 

1.247 

3-083 

0.438 

0-734 

0.428 

0.080 

0.029 

In  Tables  47  to  50  we  show  an  analysis  of  car  wheels 
given  in  a  paper  by  Mr.  S.  P.  Bush  before  the  Master 
Car  Builders'  Association,  which  were  obtained  through 
the  labors  of  Mr.  F.  D.  Casanave  and  Dr.  C.  B.  Dudley, 
both  of  the  Pennsylvania  Railway  Co.  In  referring  to 
these  wheels,  Mr.  Bush  says:  "  Twenty  wheels  were 
selected  from  those  in  service,  representing  some  of 
the  principal  makes  of  the  country,  all  of  which  were 
subjected  to  the  thermal  test,  ten  passing  it  successfully 
and  ten  failing.  Chemical  analyses  were  made  of  the 
iron  of  which  these  twenty  wheels  were  cast,  two  sets 
of  samples  being  taken  —  one  from  the  body,  or  gray 
iron,  and  the  other  from  the  chill.  The  result  of  these 
analyses  is  as  follows: 

TABLE  47 — ANALYSES  OF  THE  GRAY  IRON.   STOOD  THERMAL  TEST. 


T.  C. 

G.  C. 

C.  C. 

Man. 

Phos. 

Silicon. 

Sulphur. 

3-68 

3-00 

0.68 

0.64 

0.30 

0.56 

O.II 

3-54 

2.74 

0.80 

0.28 

0.47 

0.65 

O.IO 

3.50 

3-4« 

O.O2 

o.35 

0.40 

0.45 

0.13 

3-65 

2.41 

1.24 

0.31 

0-53 

0-57 

o.  16 

3-73 

2.89 

0.84 

0.88 

0.38 

0.50 

O.II 

3-63 

3-03 

0.60 

0.44 

0-43 

0.56 

0    12 

3-67 

2.70 

0.97 

0.24 

0.38 

0-53 

O.IO 

3.67 

3-03 

0.64 

0.32 

0.42 

0.4? 

0.  It) 

3-64 

2-53 

I.  II 

0-33 

0.50 

0.62 

O.Ii 

3-86 

3-31 

0-55 

0.30 

0.36 

0.63 

O.II 

MIXTURES    FOR    CHILL    ROLLS,    CAR    WHEELS,    ETC.      269 

TABLE   48 — DID   NOT   STAND    THREMAL   TEST. 


T.  C. 

G.  C. 

C.  C. 

Man. 

Phos. 

Silicon. 

Sulphur. 

3.64 

2.41 

1.23 

0.30 

0-35 

0.71 

0.14 

3.22 

1.98 

1.24 

0-34 

0.51 

0.77 

0.16 

3-51 

2.56 

0-95 

0.31 

0.44 

0-75 

0.12 

3.64 

2.30 

1-34 

0.21 

0-39 

0.65 

0.13 

3-6i 

2.52 

1.09 

O.I? 

0.35 

0.60 

O.I  I 

3-6i 

2.94 

0.67 

0-33 

042 

0.79 

O.I2 

3-72 

2.60 

1-13 

0.23 

0-35 

0.66 

O.I  I 

3.68 

2-54 

1.14 

0.19 

0-39 

0.88 

0.12 

3-74 

2-57 

1.17 

0.30 

0.41 

0.60 

0.13 

3-45 

2-39 

1.06 

0.40 

0.36 

0.68 

O.I9 

TABLE   49— ANALYSES    OF   THE    CHILLED    IRON. 


Stood  Thermal  Test. 

Did  Not  Stand  Thermal  Test. 

Total 
Carbon. 

Graphitic 
Carbon. 

Com. 
Carbon. 

Total 
Carbon. 

Graphitic 
Carbon. 

Com. 
Carbon. 

3-90 

0-43 

347 

3-90 

0-34 

3-56 

3-71 

0.32 

3-39 

3-37 

0.32 

3-05 

373 

0.42 

3-31 

3-71 

0-43 

3-28 

3-70 

0-55 

3-15 

3-75 

0.78 

2-97 

3.87 

0.41 

3-46 

3-74 

0.49 

2.25 

3-77 

0-55 

3-22 

3-77 

o  30 

347 
3.38~~ 

384 

0-35 

3-49 

3.86 

048 

3.84 

0.40 

344 

3-8o 

0.41 

.5-39 

3-71 

0.49 

3-22 

3-82 

0.29 

3-53 

4.01 

0.30 

3-7i 

3.56 

0.36 

3-20 

"These  figures  cover  determinations  actually  made. 
It  was  not  deemed  essential  to  determine  the  phos- 
phorus, silicon,  and  manganese  in  the  chills,  as  there 
was  no  reason  to  think  that  they  would  differ  in  propor- 
tion from  the  same  elements  in  the  gray  iron.  In 
reality  all  borings  for  the  two  analyses  were  obtained 
not  over  three  or  four  inches  apart  in  the  same  wheel, 
the  one  being  from  the  gray  iron  in  the  plate  and  the 
other  from  the  chill.  It  will  be  noted  that  in  the  gray 
iron  the  graphite  is  pretty  well  toward  3  per  cent,  and 


270 


METALLURGY    OF    CAST    IRON. 


that  the  combined  carbon  is  toward  i  per  cent.,  while 
in  the  chill  the  figures  are  reversed,  the  variations 
being  not  far  from  one-half  of  i  per  cent.  The  figures 
giving  the  analysis  of  the  gray  iron  are  given  for  a 
comparison  and  as  a  matter  of  information." 

"The  main  point  in  these  analyses  to  which  attention 
is  called  is  the  close  agreement  in  the  composition  of 
the  chills  of  these  different  wheels.  If  we  take  the 
averages  of  those  that  did  and  those  that  did  not  stand 
the  thermal  test,  we  find  as  follows:" 

TABLE    5O. 


Total 
Carbon. 

Graphi'tc 
Carbon. 

Com. 
Carbon. 

Average  of  wheels  which  stood  the  thermal  test 
Average  of  wheels  which  did  not  stand  thermal 
test  

3-8i 
3.73 

0.42 
0.42 

3-39 
3.31 

"It  will  be  noted  that  the  graphitic  carbon  is  the  same 
in  both  cases,  and  that  the  combined  carbon  only 
differs  0.08  per  cent.  Furthermore,  the  general  agree- 
ment of  the  combined  carbon  of  the  chills  in  wheels 
from  different  makers  is  very  noticeable  and  very 
remarkable.  It  is  difficult  to  see  how  any  other  con- 
clusion can  be  drawn  from  these  figures  than  that 
there  is  no  evidence,  as  far  as  the  chemical  composi- 
tion is  concerned,  to  show  that  the  chills  of  wheels 
which  stand  the  thermal  test  differ  in  their  physical 
properties  —  so  far  at  least  as  the  physical  properties 
depend  on  the  chemistry  of  the  metal  —  from  the  chill 
of  wheels  which  do  not  stand  the  thermal  test.  Also, 
it  seems  fair  to  conclude  that  wheels  made  in  different 
parts  of  the  country  and  by  different  manufacturers 
do  not  differ  very  widely  so  far  as  chemical  composi- 


MIXTURES    FOR    CHILL    ROLLS,     CAR    WHEELS,    ETC.      271 

tion  of  the  chill  is  concerned.  It  is  quite  obvious 
why  this  should  be  so,  since  the  chill  fixes  the  chemical 
composition  within  very  narrow  limits. "  In  conclusion 
Mr.  Rush  says:  ''Therefore,  to  emphasize  what  has 
been  stated  previously,  it  seems  reasonable  to  con- 
clude that  the  wear  of  ccr  wheels  depends  upon  the 
chill,  and  if  chills  of  various  wheels  are  so  closely  alike 
as  these  analyses  show  them  to  be  there  is  really  no 
evidence  that  the  wear  of  these  wheels  will  differ 
to  any  appreciable  extent. ' '  For  further  analyses  of 
car  wheels,  see  Chapter  LVIL,  page  448. 

The  sulphur,  it  will  be  noticed,  is  much  higher  in 
Tables  47  and  48  than  in  Tables  45  and  46.  Sulphur 
from  .08  to  .15  is  now  considered  by  many  to  give 
long  life  to  car  wheel  chills.  At  the  same  time,  it  is 
also  considered  necessary  to  have  manganese  range 
from  .30  to  .80  in  order  to  stand  the  thermal  test 
described  in  Chapter  LVIL  This  chapter  also  treats 
of  methods  of  testing  mixtures,  car  wheels,  and 
annealing  them.  The  depth  of  chill  required  in  wheels 
ranges  from  %  to  fo  of  an  inch  in  the  throat  and  fi 
to  i  inch  at  the  middle  of  the  thread.  Then  again, 
there  should  not  be  over  j£  of  an  inch  variation  in  the 
depth  of  chill  in  like  sections  of  the  rim.  In  making 
the  mixtures,  it  must  be  remembered  that  Tables  45 
to  50  show  analyses  of  the  iron  after  it  is  remelted  or 
in  the  castings,  so  that  the  iron  before  being  charged 
must  be  higher  in  silicon  and  manganese  and  lower  in 
sulphur,  after  the  principle  described  in  Chapter  45. 

Not  only  has  steel  and  wrought  scrap  been  mixed 
with  cast  iron  pig  mixtures,  but  steel  and  wrought  iron 
scrap  may,  for  some  classes  of  chilled  castings,  be 
mixed  wholly  with  cast  iron  scrap,  no  pig  whatever 


272  METALLURGY   OF    CAST    IRON. 

being  used.  As  an  example,  a  mixture  of  100  pounds 
of  old  horseshoes  or  any  kind  of  light  wrought  scrap, 
mixed  with  1,000  pounds  of  stove  plate  scrap,  has  been 
used  to  make  mould  boards  for  plows  and  which  gave  a 
chilled  or  white  iron  in  the  casting.  This  mixture  was 
originally  given  in  The  Foundry,  March,  1898.  A 
study  of  this  chapter  in  connection  with  the  preceding 
one  should  permit  founders  to  obtain  mixtures  for 
almost  any  line  of  chilled  castings,  but  it  must  be 
borne  in  mind  that  to  obtain  the  experience  to  success- 
fully make  chilled  castings  has  cost  founders  more 
money,  labor,  and  anxiety  than  any  other  line  of 
castings. 


CHAPTER  XXXIX. 

MIXTURES    FOR     HEAVY    AND    MEDIUM 
GRAY  IRON  CASTINGS. 

Mixtures  for  heavy  gray  iron  castings  may  consist 
of  all  charcoal  pig  iron  or  all  coke  iron ;  again,  these 
pig  irons  may  be  mixed  in  almost  any  proportion,  or 
with  scrap.  In  cases  where  heavy  castings  require 
the  best  possible  strength  cold  or  hot  blast  charcoal 
irons  are  the  best,  and  one  may  often  have  old  rails, 
car  wheels,  steel  or  wrought  scrap  mixed  with  them  to 
advantage.  In  the  case  of  massive  castings  and  utiliz- 
ing large,  heavy  scrap  with  pig  iron,  the  mixtures  are 
generally  melted  in  air  furnaces.  Cupolas  are  also 
often  used  where  the  scrap  is  not  too  large,  and  some 
obtain  excellent  strength  in  iron  by  their  use ;  never- 
theless, as  a  rule  air  furnaces  should  give  the  best 
results. 

flixtures  for  sand  rolls  are  generally  made  of  iron 
that  is  of  a  hard  nature,  and  in  some  cases  the  same 
approximate  analysis  given  for  chilled  rolls  seen  in 
Table  43  may  be  used.  Then  again,  softer  mixtures 
may  be  required  than  those  shown  in  Table  43,  and 
which  can  be  obtained  by  raising  the  silicon  or  lower- 
ing the  sulphur  and  manganese  as  shown.  Sand  rolls 
are  often  cast  with  cupola  iron,  and  such  can  be  made 
to  give  good  service  in  many  cases. 


274  METALLURGY    OF    CAST    IRON. 

Tlixtures  for  heavy  guns  should  be  made  of  iron  pos- 
sessing the  greatest  ductility,  combined  with  strength, 
that  can  be  obtained.  Cold  blast  charcoal  iron  is  the 
best  for  such  castings  and  should  be  melted  in  an  air 
furnace.  General  Rodman  obtained  from  selected 
charcoal  pig  iron  a  very  strong  gun  iron  which  had  the 
following  analysis:  Silicon  1.34,  sulphur  .003,  man- 
ganese i. oo,  phosphorus  .08,  graphitic  carbon  2.19, 
combined  carbon  .93.  The  casting  is  said  to  have 
been  tough,  with  a  fine  granular  fracture  and  a  hard 
surface  which  machined  easily ;  also  that  its  elasticity 
was  greatly  due  to  its  lowness  in  phosphorus  and 
sulphur.  Further  analyses  of  gun  mixtures  are  shown 
on  pages  278  and  299. 

flixtures  for  gun  carriages,  etc.,  as  given  by  Titus 
Ulke,  M.  E.,  in  the  Iron  Trade  Review \  December  i, 
1898,  are  found  in  the  following  four  paragraphs  and  in 
Tables  51  to  54: 

i.  Castings  weighing  from  2  to  16  tons  were  made 
for  the  United  States  barbette  and  disappearing  gun 
carriages  by  the  Lorain  Foundry  Co.,  at  Lorain,  O.,  of 
the  following  mixtures  (Table  51),  melted  in  an  air 
furnace,  the  charge  weighing  1 7  tons : 

TABLE    51. 


Charcoal  iron  scrap.                                           

35  to  45  per  cent. 
10  to  20        " 
15  to  25 
20  to  35        " 

Cold  blast  charcoal  iron  (Vesuvius  and  Salisbury)  

Warm  blast  charcoal  iron  (Rome  and  Pine  Grove)  

Coke  iron  (Napier  Dover  etc  ) 

34,000  Ibs. 

The  average  analysis  of  fifteen  heats  of  the  above 
mixture  gave  silicon  .94,  sulphur  .05,  manganese  .31, 
phosphorus  .44,  graphitic  carbon  2.40,  combined  carbon 


MIXTURES    FOR    HEAVY    GRAY    IRON    CASTINGS. 


275 


.63.     The  average  tensile  strength  is  given  as  31,350 
pounds  per  square  inch. 

2.  In  making  the  chassis  rails,  base  rings,  hydraulic 
cylinders,  and  other  parts  of  disappearing  gun  car- 
riages at  the  Niles  Tool  Works,  Hamilton,  O.,  the 
following  mixture  (Table  52),  melted  in  a  cupola, 
was  used  : 

TABLE    52. 


No.  3  Muirkirk  charcoal  iron  

5     to  15  per  cent 

No.  4^  Muirkirk  charcoal  iron 

3^  to  15        " 

No.  4  high  lyandon  charcoal  iron                                .   .. 

25      to  30        " 

No.  4  low  lyaiidoii  charcoal  iron.        

3°        " 

Gun  iron  scrap  

20     to  25        " 

Total  

100  per  cent. 

The  analysis  of  this  cupola  iron  gave  silicon  about 
i. oo,  sulphur  .05,  manganese  .6,  phosphorus  .3,  graph- 
itic carbon  1.40,  combined  carbon  i.  to  1.20.  The 
tensile  strength  is  given  as  about  33,000  pounds,  on  an 
average,  and  the  elongation  from  .5  to  .  6  of  i  per  cent. 
The  above  Landon  iron  is  made  by  the  Salisbury  Car- 
bonate Iron  Co.  (See  page  278.) 

3.  A  mixture  made  at  the  Columbus  Machine  Co.  's 
works,  Columbus,  O.,  which  gave  very  satisfactory 
results  with  the  iron  melted  in  a  cupola  is  as  follows : 

TABLE  53. 


Muirkirk  charcoal  iron  

15  per  cent. 

Salisbury  charcoal  iron  

25        " 

Enibreville  coke  iron  (high  in  C)  

20           " 

Gun  iron  scrap.                                    . 

3°        " 

Steel  (bloom  ends) 

10        " 

Total. 

100  per  cent. 

The  above  gun  mixture  analyzed:  Silicon  1.53,  sul- 


276  METALLURGY    OF   CAST    IRON. 

phur  .05,  manganese  .45,  phosphorus  .29,  graphitic 
carbon  3.01,  combined  carbon  .42,  and  iron  93.98, 
making  a  total  of  99. 74.  The  tensile  strength  averaged 
over  30,000  pounds,  and  the  elongation  .4  per  cent. 

4.  In  making  semi-steel,  melted  in  a  cupola  at  the 
Rarig  Engineering  Co. ,  near  Columbus,  O. ,  the  follow- 
ing mixture  (Table  54),  was  used: 

TABLE    54. 


Lawrence  pig  (No.  2)  

59.3  to  69    per  cent. 

Homogeneous  steel  (boiler  plate  scrap). 

on  6  to  ^o         " 

Ferro-manganese,  12  to  15  Ibs.  per  ton  . 

6  to  o  8      " 

Alloy  in  ladle,  8  to  10  Ibs.  per  ton  

•4  to  0.5      " 

Total  

100  per  cent 

An  alloy  composed  of  the  following  elements  Al. 
2.00,  Mn.  8.71,  Si.  .22,  P.  .09,  Fe.  89.06,  which  was  in  a 
granulated  form,  was  put  into  the  ladle  to  flux  the 
metal  as  described  on  next  page.  The  analysis  of  the 
"  semi-steel  "  castings  gave  Si.  .98,  S.  06,  Mn.  .43,  P. 
.43,  G.  Car.  .96,  C.  Car.  .75.  This  metal  gave  an  aver- 
age tensile  strength  in  three  castings  of  34, 700  Ibs.  per 
square  inch.  The  castings  are  said  to  have  been 
found  free  of  blow  holes  and  other  defects  which  are 
sometimes  found  in  semi-steel  castings. 

In  commenting  on  "semi=steel,"  so  called,  Mr.  Ulke 
says  that  it  was  used  as  far  back  as  1873.  It  was  a* 
that  time  made  by  Mr.  Sleeth  of  Pittsburg,  Pa.,  and 
cast  into  chilled  or  dry  sand  rolls  and  pinions  of  superior 
quality.  Long  before  1873,  however,  wrought  iron  or 
steel  scrap  had  been  used  in  making  special  grades  of 
cast  iron,  such  as  tough  cast  iron  for  drop-hammer  dies 
and  for  similar  castings.  Certainly  the  use  of  steel 
scrap  or  of  similar  material  in  a  cupola,  or  in  a  ladle  is 


MIXTURES    FOR    HEAVY    GRAY    IRON    CASTINGS.          277 

not  a  modern  or  patentable  idea.  There  is  no  fad  or 
physic  necessary,  although  a  *  *  secret ' '  dope  is  some- 
times used  by  so-called  inventors,  chiefly  in  order  to 
throw  a  veil  of  mystery  over  a  quite  simple  process.  An 
analysis  of  one  of  these  expensive  "  medicines, "  which, 
however,  possibly  serves  a  useful  purpose  by  agitating 
or  mixing  the  metal  in  the  ladle  and  perhaps  reducing 
its  sulphur  contents,  is  given  in  the  preceding  paragraph. 

''The  phenomenal  tensile  strength  (49,000  pounds  and 
above)  claimed  for  certain  gun  iron  and  semi-steel 
castings  is  also  misleading,  if  the  size  and  treatment 
of  the  attached  test  coupons  is  not  stated,  as  we  shall 
see  later.  Tests  have  been  and  are  frequently  reported 
as  correct  —  i.  e. ,  as  fairly  representing  the  pieces  the 
physical  qualities  of  which  they  are  intended  to  deter- 
mine—  when  in  reality  they  are  from  3,000  to  10,000 
pounds  per  square  inch  too  high.  This  is  due  to  the 
fact  that  the  coupons  cast  on  are  only  i  to  i^  inches 
round  instead  of  3  inches,  on  castings  3  inches  in  sec- 
tion, and  therefore  chill  and  harden  more  rapidly  and 
show  a  correspondingly  higher  strength  than  the  cast- 
ings."  In  conclusion  Mr.  Ulke  says:  "  The  depth  to 
which  the  '  chill '  penetrates,  as  determined  by  special 
chill -blocks  6x4x1^  inches  in  size,  cast  in  special 
moulds  in  the  same  heat  as  the  pieces,  is  a  good  in- 
dication of  the  tensile  strength  of  the  semi-steel  cast, 
and  serves  the  foundryman  as  a  simple  and  convenient 
guide  for  grading  his  metal. ' ' 

flelting  gun  iron  mixtures  in  cupolas  has  given  some 
exceptional  results,  as  will  be  seen  by  the  excellent 
strengths  shown  in  Tables  52  to  55.'  These  Salisbury 
irons  have  been  used  by  large  concerns,  and  are  spoken 
of  in  the  Iron  Trade  Review  of  December  15,  1898,  as 


278  METALLURGY    OF    CAST    IRON. 

having  given  very  satisfactory  results.  The  iron  was 
melted  with  good  Connellsville  coke  in  a  cupola  after 
regular  practice.  This  is  a  high-priced  iron  made  by 
the  Salisbury  Carbonate  Iron  Co.,  one  furnace  being 
located  at  Chapinville,  Conn.  It  is  very  evident  by 
the  extract  seen  below  that  the  Salisbury  and  Muirkirk 
irons  are  rivals  for  the  patronage  of  those  making 
strong  castings. 

TABLE    5  5.  —TENSILE   STRENGTH   TESTS   OF  HIGH   GRADE  SALISBURY 
CARBONATE  IRON. 

Heat  Oct.  isth,  1898.     Castings  in  weight  from  500  to  18,000  Ibs. 
%  Salisbury  carbonate  iron,  No.  4  ...................................................  l-wR     Ibs 

Heat  Oct.  21,  1898.    Castings  as  above. 
|  Salisbury  carbonate  iron,  No.  4  ^.  ............................................  |35(32O  lb, 


Heat  Oct.  29,  1898.     Castings  as  above. 
50  per  cent  Salisbury  carbonate,  No.  4  ..............................................  } 

30  No.  4,  high  .......................................  >  34,  800  Ibs. 

20  scrap...  ...........................................  ) 

Obtaining  strong  iron  from  cupolas  is  a  subject  which 
interests  many,  and  to  have  others'  experience  than 
the  author  we  give  space  to  an  extract  of  an  article  pub- 
lished in  the  Iron  Trade  Review  December  29,  1898, 
as  follows:  "It  is  probably  not  known  to  the  trade 
generally  that  Muirkirk  pig  iron  was  the  first  iron  to 
be  used  successfully  in  the  manufacture  of  gun  iron 
castings  for  the  United  States  Government,  by  melting 
in  the  cupola.  Such,  however,  is  the  fact;  and  the 
credit  of  being  able  to  make  gun  iron  castings  in  the 
cupola  that  would  stand  the  tests  of  the  United  States 
Government  for  gun  carriage  work  rightfully  belongs 
to  Messrs.  Robert  Poole  &  Son  Co.  of  Baltimore,  Md., 
and  Muirkirk  pig  iron  made  by  me.  This  was  in  1893. 
The  War  Department  at  first  refused  to  accept  cupola 
iron  as  gun  iron,  but  when  it  was  fully  demonstrated 


MIXTURES    FOR    HEAVY    GRAY    IRON    CASTINGS.          279 

that  the  iron  was  fully  the  equal  of  *  air  furnace  gun 
iron, '  they  were  satisfied.  The  great  strength  and 
value  of  Muirkirk-  pig  iron  is  not  a  question  of  a  few 
years,  but  has  been  known  since  the  building  of  the 
furnace  in  1841,  or  over  fifty  years.  Muirkirk  was 
used  during  the  Civil  War  for  shot,  shell,  and  cannon. 
It  was  used  in  the  manufacture  of  the  last  cast  gun 
iron  mortars  made  for  the  United  States  War  Depart- 
ment, and  was  used  at  the  United  States  Navy  Yard, 
Washington,  D.  C.,  for  the  manufacture  of  cast  iron 
shells  until  steel  was  substituted.  The  fact  is  that 
until  a  few  years  ago  there  was  no -iron  that  could  com- 
pete in  any  way  with  Muirkirk  pig  iron  for  strength 
and  elasticity,  and  now  there  is  none  that  would  be 
preferred  at  the  same  price  per  ton.  I  have  had 
charge  of  and  practically  owned  this  furnace  for  the 
past  thirty-five  years.  I  think  I  can  truly  say  that  I 
never  have  lost  a  customer  except  on  account  of 
price  —  never  on  account  of  quality. 

CHAS.  E.  COFFIN." 

Muirkirk,  Prince  George's  County,  Md. 
The  need  of  cheap  mixtures  for  medium  and  heavy 
castings,  often  calls  for  the  use  of  coke  and  anthracite 
irons  which  carry  a  large  percentage  of  iron  or  steel 
scrap.  Mixtures  are  made  of  these  irons  that  often 
come  close  to  the  strength  given  in  Tables  52  to  55  for 
charcoal  iron  mixtures.  Such  castings  as  given  in 
Nos.  23,  25  to  35,  Chapter  XXXV.,  page  252,  are 
largely  made  of  coke  or  anthracite  iron  mixed  with 
scrap.  As  much  as  80  per  cent,  of  ordinary  unburnt 
clean  gray  scrap  iron  can  be  mixed  with  20  per  cent, 
of  4  per  cent,  silicon  pig  iron  for  many  lines  of  cast- 
ings more  than  i  yz  inches  in  thickness,  and  requiring 


280 


METALLURGY    OF    CAST    IRON. 


to  be  machined.  In  castings  not  requiring  a  finish, 
such  a  mixture  may  be  used  in  castings  as  thin  as  % 
of  an  inch  and  still  be  soft  enough  to  permit  being 
chipped  in  the  cleaning. 

The  general  run  of  castings  ranging  from  ^  to  4 
inches  in  thickness,  that  require  to  be  sufficiently  soft 
to  be  machined  and  possess  similar  strength  per  square 
inch,  may  often  range  in  analysis  of  mixtures  as  seen 
in  the  approximate  Table  56.  It  is  understood  that 
these  analyses  include  pig  iron  and  scrap  mixed,  or  pig 
alone,  as  either  mixture  would  stand  ready  for  charg- 
ing. It  is  not  to  be  expected  .that  the  sulphur,  man- 
ganese, phosphorus,  and  total  carbon  can  be  obtained 
in  keeping  with  the  increase  of  silicon  shown.  How- 
ever, should  the  sulphur  or  manganese  be  increased 
from  that  shown  in  the  Table,  the  silicon  should  be 
increased  in  such  a  proportion  as  to  maintain  a  hard- 
ness similar  to  that  obtainable  by  the  analyses  shown. 

Should  the  total  carbon  be  higher  than  shown  for 
the  larger  thickness  then  the  silicon  would  require  to 
be  proportionately  lower  to  maintain  similar  strengths 
or  hardness.  It  is  to  be  remembered  that  as  a  rule  the 
total  carbon  comes  highest  in  low  silicon  irons,  which 
is  the  reverse  of  the  order  shown  for  carbon  in  Table 
56,  see  chapter  XXXIII,  page  247. 

TABLE   56. — APPROXIMATE  ANALYSES  OF   COKE  IRON   MIXTURES. 


Thickness 
of  Casting. 

Silicon. 

Sulphur. 

Manga- 
nese. 

Phos- 
phorus. 

Total  Carbon. 

%" 

2-75 

.02 

•3° 

.70 

3.75  to  4.00 

i11 

2.50 

.02 

•30 

-65 

3.50  to  3.75 

w 

2.25 

.02 

.40 

.60 

3.25  to  3.50 

2" 

2.00 

•03 

.40 

•55 

3.00  to  3.25 

*Vl" 

1-75 

•03 

•5° 

•.S" 

2.75  to  3.00 

3" 

1.50 

•03 

•5° 

•45 

2.50  to  3.00 

31A" 

1-25 

.04 

.60 

.40 

2.50  to  3.00 

4" 

I.OO 

.04 

.70 

•35 

2.50  to  3.00 

CHAPTER  XL. 

MIXTURES  FOR  LIGHT  MACHINERY  AND 
STOVE  PLATE  CASTINGS. 

flixtures  for  light  machinery,  sewing  machines,  stove 
plate,  hollow  ware,  and  hardware,  etc.,  castings  call 
for  very  soft  grades  of  iron.  In  making  such  cast- 
ings it  is  rarely  wise  to  use  any  other  iron  than  pig 
and  shop  scrap.  As  a  rule  there  is  much  more  shop 
scrap  obtained  from  making  light  work  castings  than 
from  heavy  ones.  In  light  work  the  shop  scrap  gen- 
erally ranges  from  25  to  40  per  cent,  of  the  weight 
necessary  to  be  charged  for  a  heat.  As  melting  iron 
hardens  it,  there  must  of  necessity  be  sufficient  silicon 
added  every  heat  to  restore  the  scrap  to  the  mixture's 
original  softness.  For  this  reason  light  work  shops 
generally  find  that  theii  own  shop  scrap  is  all  they  can 
wisely  use. 

The  percentage  of  silicon  in  light  work  mixtures,  as 
they  stand  ready  for  charging  —  which  includes  an 
average  of  the  silicon  in  the  pig  and  shop  scrap  —  may 
range  from  3.00  to  3.80.  This  would  give  a  silicon  in 
the  castings  resulting  from  the  mixture  of  such  pig 
and  shop  scrap  of  from  2.70  to  3.50,  according  to  the 
grade  of  softness  desired  in  the  castings.  When  the 
silicon  exceeds  3.75  in  castings  the  body  or  surface 
may  be  often  found  harder  than  with  lower  silicon. 
This  is  much  affected  by  the  percentages  of  total  car- 


282  METALLURGY    OF    CAST    IRON. 

bon,  sulphur,  phosphorus,  and  manganese  in  the  iron. 
The  more  total  carbon  the  less  silicon  required,  on 
account  of  carbon  softening  iron,  as  can  be  seen  by  a 
study  of  Chapter  XXXIII.  The  following  Table  57 
gives  an  approximate  idea  of  the  highest  silicon  con- 
tents it  is  generally  wise  to  have  in  soft  or  light  cast- 
ings, in  combination  with  the  total  carbon ;  the  other 
elements,  sulphur,  manganese,  and  phosphorus  being 
fairly  constant  at  the  respective  percentages  consid- 
ered best  for  making  soft  castings: 

TABLE    57. 


Silicon. 

3-75 

3-7° 

3.65 

3.6o 

3  55 

3-5° 

Total  Carbon  

3-oo 

3-25 

3-50 

3-75 

4.00 

4-25 

The  percentage  of  sulphur,  manganese,  and  phos- 
phorus generally  found  in  light  castings  is,  as  a  rule, 
.06  to  .08  sulphur,  .40  to  i. oo  manganese,  and  .50  to 
1.25  phosphorus.  It  will  be  readily  understood,  from 
a  study  of  Chapters  XXIX.  to  XXXII.,  that  an  increase 
of  sulphur  and  manganese  hardens  iron,  while  phos- 
phorus increases  fluidity  and  brittleness,  and  that  for 
thin  or  light  castings  requiring  very  fluid  metal  high 
phosphorus  is  necessary.  As  iron  for  light  castings 
must  generally  be  soft,  care  should  be  taken  not  to 
let  the  sulphur  and  manganese  exceed  the  above 
amounts  in  castings.  To  obtain  these  percentages 
in  castings  it  will,  of  course,  be  necessary  to  have 
less  sulphur  and  higher  manganese  in  the  mixtures 
before  being  charged,  as  is  explained  in  Chapter  XLV. 

The  same  regular  analyses  in  different  mixtures  of 
irons  may  not  give  like  softness  in  castings.  This 
may  be  due  to  the  quality  described  on  pages  161  and 
261,  or  to  some  brands  of  iron  possessing  more  of  a 


MIXTURES    FOR    LIGHT    MACHINERY,    ETC.  283 

chilling1  quality  than  others,  often  due  to  some  special 
peculiarity  of  the  ores  from  which  the  iron  was  made, 
or  working  of  the  furnace,  and  which  might  often  be 
explained  were  analyses  carried  beyond  determin- 
ing the  regular  five  elements.  However,  it  is  often 
well  for  a  founder,  in  starting  to  make  light  or  stove 
plate  castings,  to  purchase  pig  iron  (after  the  methods 
described  in  page  200)  from  the  furnaces  that  can  show 
their  irons  are  being  successfully  used  by  other  light 
work  or  stove  plate  foundries. 

If  any  yard  or  foreign  scrap  iron  is  used,  care  should 
be  taken  to  have  it  clean  and  free  as  possible  from  rust 
or  oxide  of  iron ;  also,  no  burnt  iron  should  be  used, 
as  such  will  greatly  cause  mixtures  to  give  hard  iron 
in  light  work.  (Facts  treated  further  in  pages  295 
to  297.)  The  best  test  for  softness  in  light  work 
castings  generally  lies  in  the  castings  themselves, 
as  almost  every  light  casting  if  not  of  a  sufficiently 
soft  character  is  readily  told  by  means  of  a  file,  grind- 
stone, or  chisel.  If  light  castings  crack,  it  is  generally 
evidence  of  the  iron  being  too  high  in  sulphur  or  phos- 
phorus, or  too  low  or  high  in  silicon,  which  latter  can 
be  told  readily  by  an  examination  of  the  fracture,  as 
if  they  are  too  low  in  silicon  the  edges  of  the  casting 
will  show  a  greater  chill  than  from  an  excessive  use  of 
silicon.  Then  again,  the  latter  will  give  a  very  brittle 
body,  while  the  former  will  be  of  a  stronger  character. 
It  is  to  be  remembered  that  there  is  a  limit  to  the  use 
of  silicon  in  affording  softness,  and  that  it  can  make 
very  brittle  castings,  as  shown  on  page  209. 


CHAPTER  XLI. 


MIXTURES   AND    ELEMENTS   DESIRABLE 
FOR  ELECTRICAL  WORK. 

Castings  for  electrical  work  were  supplied  by  our 
foundry  for  several  years  to  a  leading  manufacturer. 
It  was  with  much  surprise  that  we  found,  when  first 
commencing  this  work,  that  no  one  in  the  plant  using 
our  castings  knew  what  chemical  properties  were  es- 
sential to  exist  in  their  dynamos,  other  than  that  the 
buyer  wanted  them  soft,  as  it  was  found  that  a  hard 
metal  resisted  the  action  of  the  current  and  did  not 
form  a  good  magnetic  conductor.  To  give  an  idea  of 
what  properties  are  essential  in  castings  for  electric 
work,  the  following  analyses  of  drillings  which  were 
taken  from  a  dynamo  casting  for  the  author,  which  had 
proven  to  possess  good  electrical  induction  or  magnetic 
permeability,  is  presented :  * 

TABLE    58. — CHEMICAL   ANALYSIS   OF   DYNAMO    IRON. 


Silicon. 

Sulphur. 

Phos- 
phorus. 

Manga- 
nese. 

Graph. 
Carbon. 

Comb. 
Carbon. 

Total 
Carbon. 

3.190 

•075 

.890 

•350 

2.890 

.060 

2.950 

A  study  of  the  above  analysis  will  show  the  product 
to  be  a  very  soft  iron,  which  in  a  general  sense  covers 
the  requirements ;  and  when  it  is  said  that  all  elements 
should  be  avoided  which  favor  the  formation  of  com- 
bined carbon,  the  founder  has  a  key  to  guide  him  in 


*  For  the  relative  conductivity  of  different  metals  for  heat  and 
electricity,  see  Table  135,  page  593. 


ELEMENTS    DESIRABLE    FOR    ELECTRICAL    WORK.       285 

making  mixtures  for  castings  expected  to  convey  elec- 
tric currents. 

It  will  be  seen  that  the  silicon  in  the  above  analysis 
is  as  high  as  3.190,  a  point  rarely  attained  in  other 
specialties  of  casting,  but  it  will  be  noticed  that  the 
sulphur  is  also  well  up,  so  that  it  greatly  neutralizes 
the  softening  effect  of  the  silicon.  If  the  sulphur 
were  about  .050,  the  same  softness  would  be  obtained 
with  about  2.60  of  silicon,  so  powerful  is  the  effect  of 
a  few  points  in  sulphur  to  promote  combined  carbon. 

In  testing  a  casting  to  discover  its  degree  of  softness 
by  analysis,  it  is  usually  best  to  first  find  its  percent- 
age of  combined  carbon,  which  should  not  exceed  .  70 
and  is  best  kept  down,  if  possible,  to  about  .  30.  If  an 
analysis  shows  the  combined  carbon  to  be  too  high, 
then  determinations  should  be  made  of  the  sulphur 
and  silicon  contents  of  the  iron,  to  learn  if  either  of 
these  elements  is  at  fault,  as  these  properties  are  the 
bases  in  changing  the  * '  grade  ' '  of  iron  to  control  the 
carbon  in  taking  the  graphitic  or  combined  form. 
The  higher  the  carbon,  and  the  more  it  is  thrown  into 
the  graphitic  form,  the  better  the  iron  for  electric  work. 

The  effect  of  high  phosphorus  is  to  slightly  re- 
tard softness,  and  for  this  reason  it  is  also  best  kept 
as  low  as  is  consistent  in  obtaining  the  fluidity  de- 
sired. Phosphorus  should  not  exceed  .80,  unless 
some  very  thin  castings  are  to  be  made,  or  there  are 
parts  in  heavy  castings  difficult  to  ' '  run ; ' '  then  phos- 
phorus may  be  allowed  to  approach  i.oo. 

Manganese  in  iron  for  electric  work  is  also  a  factor 
which  requires  watching,  as  its  tendency  is  to  promote 
hardness  or  combined  carbon.  It  is  best  not  to 
exceed  .40,  unless  the  silicon  is  over  3.00  and  the 


286  METALLURGY    OF    CAST    IRON. 

sulphur  under  .060,  then  the  managanese  might  be  pci 
mitted  to  go  higher.  Manganese  is  somewhat  decep- 
tive, as  it  will  permit  a  casting  to  arrange  its  crystals 
in  large  grains,  giving  the  iron  the  appearance  of  be- 
ing high  in  graphite  when  at  the  same  time  the  metal 
is  much  harder  than  if  the  large  grains  were  all  the 
result  of  silicon  in  giving  the  iron  large  grains. 

By  a  study  of  this  Chapter  it  will  be  observed  that 
the  state  of  the  combined  carbon  is  the  chief  factor  in 
determining  the  utility  of  a  casting  for  electrical  pur- 
poses. We  have  stated  that  it  is  desirable  that  com- 
bined carbon  should  not  exceed  .70  in  any  casting.  It 
is  to  be  remembered  that  the  thickness  of  a  casting 
and  the  time  it  takes  the  molten  metal  to  solidify 
have  also  a  great  influence  in  determining  what  per- 
centage of  combined  carbon  a  casting  will  contain. 
The  more  quickly  a  casting  cools  the  higher  will  be  its 
percentage  in  combined  carbon.  For  this  reason- it  will 
be  evident  that  thin  castings  would  require  higher  silicon 
and  lower  sulphur,  also  manganese,  than  thick  castings. 

With  all  the  above  elements  to  influence  the  forma- 
tion of  combined  carbon,  it  is  evident  that  it  would 
not  be  practical  to  here  attempt  to  prescribe  what  per- 
centage of  sulphur  and  silicon  a  mixture  should  con- 
tain. All  that  can  be  done  is  to  illustrate  the  funda- 
mental principles  involved,  and  these,  as  here  stated, 
taken  in  connection  with  the  effect  re-melting  of  iron 
has  in  increasing  or  decreasing  the  chemical  properties 
of  a  mixture,  as  outlined  in  Chapter  XLV.,  page  302, 
will  permit  any  founder  making  a  study  of  this  chapter 
to  intelligently  formulate  a  mixture  which  will  work 
well  for  any  thickness  of  castings  to  be  used  for  elec- 
trical purposes. 


CHAPTER  XLII. 

MIXTURES  FOR  WHITE   IRON   CASTINGS 
AND  EFFECTS  OF  ANNEALING  THEM. 

There  are  castings,  such  as  are  used  for  base  plates 
in  crushers,  dies,  etc.,  that  are  best  made  of  all  white 
iron.  In  making  mixtures  for  such  work  the  thickness 
of  the  casting  as  well  as  the  character  of  the 
iron  should  be  considered,  as  if  this  is  not  done 
castings  that  were  desired  to  be  white  can  be  so 
thick  as  to  cause  the  resulting  iron  to  be  mottled  or 
gray.  It  must  also  be  remembered  that  there  is  a 
difference  in  the  strength  of  white  irons,  and  that  such 
castings  can  be  made  from  burnt  or  oxidized  iron, 
which  will  be  weaker  than  those  made  of  regular  clean 
or  unburned  iron.  Then  again,  charcoal  iron  can  give 
stronger  white  iron  than  coke  or  anthracite  iron.  To 
give  an  approximate  idea  of  the  silicon  in  white  iron 
mixtures,  for  making  white  castings,  the  following 
Table  59  is  presented.  The  sulphur  is  supposed  to  be 
held  at  .10  to  .15,  manganese  .50  to  .75,  and  phos- 
phorus .25  to  .50.  If  sulphur  or  manganese  are  higher 
than  shown,  then  the  silicon  could  be  increased,  or 
vice  versa.  The  following  analysis  is  supposed  to  be 
that  existing  in  the  castings,  and  which  would  mean 
that  the  silicon  should  be  .10  to  .20  per  cent,  higher 
and  the  sulphur  two  to  three  points  lower  in  the  iron 
charged  for  making  the  casting : 


288 


METALLURGY    OF    CAST    IRON. 


TABLE    59. 


Thickness  1 
of  casting,  j 
Percentage  1 
of  silicon,   j 

W 

i* 

ifc* 

2" 

2^" 

3" 

3^" 

4" 

.90 

.70 

.60 

•50 

40 

•30 

•25 

.20 

In  melting  white  iron  mixtures  the  iron  should  be 
brought  down  ' '  hot, ' '  and  care  taken  not  to  let  it  get 
too  near  the  danger  point  of  becoming  sluggish  before 
pouring.  White  iron,  being  low  in  silicon,  or  high 
in  sulphur,  will  cool  very  rapidly  when  it  reaches  a 
temperature  where  the  eye  can  detect  it  commencing 
to  lose  fluidity.  As  a  general  thing  the  gates  for  pour- 
ing white  iron  castings  should  be  made  from  one -third 
to  one-half  larger  than  for  gray  iron,  in  order  that  the 
iron  may  fill  the  mould  rapidly.  If  castings  over  2 
inches  thick  are  desired  to  be  solid  on  their  interior, 
feeding  will  be  found  necessary  and  much  care  and 
skill  are  required  in  the  feeding,  as  white  iron  has  great 
shrinkage  and  contraction.  These  two  factors  are 
about  as  •  great  again  as  in  gray  iron.  A  contraction 
of  about  Y^  inch  per  foot  is  generally  allowed  for 
white  iron  in  castings  %-inch  thick.  As  they  increase 
in  thickness  the  less  of  course  the  contraction. 

White  iron  can  be  made  gray  and  malleable  by 
annealing ;  in  fact,  malleable  castings  are  white  iron 
annealed.  The  principle  involved  consists  in  packing 
the  white  iron  castings  in  cast  or  wrought  pots  or 
boxes  surrounded  with  iron  oxides,  generally  in  the 
form  of  rolling  mill  scale  and  wrought  or  steel  turn- 
ings, the  whole  sometimes  treated  with  a  solution  of 
sal  ammoniac.  Then  again,  hematite  ores  are  used. 
In  the  selection  of  such  iron  oxides  care  is  taken  to 
have  them  as  free  of  sulphur  as  possible,  especially  for 


MIXTURES    FOR    WHITE    IRON    CASTINGS,    ETC.          289 

small  casting's.  The  oxide  withdraws  carbon  and  what 
remains  exists  mainly  as  temper  carbon,  a  form  simi- 
lar to  graphite  but  not  crystallized.  The  decarboniz- 
ing of  castings  is  greatest  near  the  surface.  The 
interior  of  thick  castings  often  gives  up  little  if  any 
carbon.  This  causes  thin  castings  to  appear  much 
more  malleable,  or  ductile,  than  thick  ones.  The 
reason  of  this  will  be  better  understood  when  it  is 
stated,  as  shown  by  Dr.  R.  Moldenke,  that  in  analyz- 
ing a  ^s -inch  malleable  casting  with  the  ends  broken 
off,  which  was  placed  in  the  shaper  and  i-i6-inch  cuts 
taken  off,  the  first  cut  analyzed  .  1 6  total  carbon,  the 
second  .65,  the  third  1.84,  the  next  3.97,  and  the  last 
4.05  per  cent.  The  original  casting  contained  4.08  per 
cent,  of  total  carbon,  thus  showing  that  the  interior  of 
thick  malleables  may  be  but  little  changed.  This  has 
caused  an  impression  that  fa  of  an  inch  was  as  thick 
as  was  practicable  for  good  malleables.  The  process 
of  annealing,  lengthens  castings  to  such  an  extent  as  to 
expand  them  about  ^  of  an  inch  per  foot.  The  lighter 
the  casting,  the  relatively  greater  the  expansion. 
This  expansion  greatly  counteracts  the  excessive  con- 
traction which  must  be  allowed  in  making  patterns, 
and  is  such  as  to  usually  call  for  no  greater  contraction 
than  in  making  patterns  for  gray  iron  castings 

The  percentage  of  silicon  used  for  malleables  to  get 
white  iron  in  castings  ranges  from  .60  to  1.25,  running 
lower  with  the  thickness.  The  iron  for  making  mal- 
leables is  melted  in  the  cupola,  air,  and  open-hearth 
furnaces.  The  cupola  is  generally  used  for  light  cast- 
ings as  it  gives  a  better  opportunity  to  obtain  very 
fluid  iron,  which  will  permit  its  being  carried  in  small 
ladles  to  the  moulds,  than  that  coming  from  furnaces 


290  METALLURGY    OF    CAST    IRON. 

which  are  generally  used  for  large  castings  which 
permit  of  refining,  testing,  and  changing  the  character 
of  the  mixture  somewhat  before  the  metal  is  tapped 
into  ladles.  The  Siemens-Martin  acid  open-hearth 
furnace  is  now  being  very  successfully  employed  for 
heavy  castings.  These  furnaces  are  much  hotter  than 
air  furnaces.  The  temperature  of  metal  in  th.em  rises, 
possibly,  to  3,500  to  4,000  degrees  F.  This  permits 
the  practice  of  using  much  steel  scrap  in  with  the  low 
silicon  iron  to  lower  the  total  carbon  slightly,  which  is 
a  desirable  point  in  making  malleables  as  it  gives  a 
metal,  after  annealing,  softer  and  tougher  on  account 
of  the  lower  total  carbon  than  is  practicable  with  air 
furnace  or  cupola  irons.  Small  quantities  of  iron  ore 
have  been  added  by  some  thinking  to  assist  in 
reducing  the  carbon  but  such  is  no  longer  practiced. 
One  disadvantage  of  furnaces  over  cupolas  lies  in  the 
loss  of  iron,  as  the  former  often  causes  a  loss  of  12  per 
cent,  of  the  iron  charged  by  reason  of  scintillation  and 
oxidation  of  the  metal's  surface  when  exposed  to  the 
flame. 

The  process  of  annealing  is  one  that  varies  greatly 
with  different  firms.  One  firm  may  anneal  similar 
thicknesses  of  castings  in  half  the  time  another  will 
take.  The  changes  effected  by  annealing  are  chiefly 
in  lowering  the  total  carbon  in  the  skin  and  turning 
the  combined  that  remains  into  temper  carbon,  the 
silicon,  sulphur,  manganese,  and  phosphorus  remain- 
ing practically  the  same.  The  time  occupied  in 
annealing  ranges  from  one  to  seven  days,  with  cast- 
ings packed  in  boxes,  etc.  This  wide  difference  is  due 
to  different  customs  and  the  character  of  castings  to 
be  treated.  The  ovens  used  are  of  simple  construction 


MIXTURES    FOR    WHITE    IRON    CASTINGS,    ETC.  291 

and  generally  of  rectangular  form,  being  in  size  about 
eight  feet  high  in  the  center  of  the  arch,  by  ten  feet 
wide  and  eighteen  feet  long.  The  castings  are  placed 
in  rectangular  pots,  which  are  set  upon  the  bottom 
and  often  built  four  or  five  high  until  a  furnace  is 
filled.  The  ovens  are  heated  with  natural  and  pro- 
ducer gas ;  also  coke  and  coal.  The  action  is  purely 
one  of  heating,  and  the  temperature  ranges  from  1,400 
to  1,900  degrees  F. 

Some  firms  anneal  castings  without  packing  them, 
placing  them  in  the  ovens  singly  and  allowing  the  heat 
to  come  in  direct  contact  with  their  surfaces.  This  is 
generally  done  only  with  work  that  is  not  particular, 
as  the  heat  scales  the  castings  badly.  Malleable  people 
in  general,  when  an  order  is  very  urgent,  will  often 
anneal  castings  outright  in  the  melting  furnace.  The 
results,  however,  are  very  unreliable  and  cause  the 
surface  to  look  badly.  The  effect  is  generally  an 
incomplete  conversion  of  the  combined  carbon  to  the 
temper  carbon.  Annealing  is  like  other  workings  in 
iron,  there  are  many  little  things  that  must  be  learned 
by  experience  before  success  can  be  had. 


CHAPTER  XLIII. 

CHEMICAL  FORMULA    FOR    MIXING  AND 
MELTING  SCRAP  IRON. 

Scrap  iron,  as  a  general  thing,  is  a  product  which 
has  been  re-melted  one  or  more  times,  and  hence  must 
fairly  show  its  true  grade  in  a  clean  fracture.  The  ad- 
vent of  chemistry  in  founding  will  naturally  cause 
some  to  ask :  is  it  not  necessary  to  know  the  metalloids 
in  scrap  iron  as  well  as  in  pig  metal  in  order  to  obtain 
desired  results  from  mixtures?  It  is,  of  course,  well 
to  have  analyses  of  scrap  the  same  as  with  pig  metal, 
whenever  this  is  practical,  but  owing  to  the  fact  that 
scrap  generally  comes  to  the  founder  in  a  promiscuous 
manner,  often  a  little  of  everything,  working  by  analy- 
sis becomes  largely  impractical,  either  as  to  obtain- 
ing actual  analyses  or  attempting  to  guess  the  chemic- 
al properties.  In  reality,  it  is  not  practical  to  define 
any  of  the  metalloids  in  scrap  iron  by  guesswork. 
About  the  only  practical  plan  which  the  author  can 
suggest  is  to  consider  and  class  scrap  in  the  order  of 
4 'grades,"  by  numbers:  as,  for  example,  build  an  im- 
aginary base  to  define  "  grades  "  from  the  texture  and 
grain  which  would  be  obtained  by  the  remelting  of  pig 
metal,  say,  containing  i.oo,  2.00,  and  3.00  per  cent,  of 
silicon,  respectively,  with  sulphur  supposed  to  be  con- 
stant at  .  030  and  phosphorus  and  manganese  as  gen- 


MIXING    AND    MELTING    SCRAP    IRON.  293 

erally  found  in  their  foundry  iron,  in  all  the  three 
mixtures.  By  such  a  method  any  founder  having 
had  experience  in  following  chemistry  to  any  degree 
will  soon  know  what  ' '  grade  ' '  the  above  mixtures  of 
pig  metal  would  give  were  they  poured  into  castings 
ranging  from  stove  plate  up  to  bodies  six  inches  thick, 
and  then,  when  sorting  scrap  in  "  grades,"  they  would 
simply  be  contrasted  with  the  '  *  grade  ' '  produced  by  the 
imaginary  pig  mixture  which  had  been  taken  to  define  a 
base  for  a  grade  desired.  By  following  such  a  method 
as  this,  it  is  very  evident  that  the  grading  of  scrap 
iron  could  be  reduced  to  a  very  satisfactory  system,  in 
all  work  where  it  is  economical  to  utilize  scrap  iron. 

As  a  general  thing,  founders  are  desirous  of  utilizing 
all  the  outside  scrap  possible  in  mixture  with  pig 
metal,  because  it  can  generally  be  bought  for  less 
than  pig  iron.  With  work  that  permits  a  good  leeway  in 
the  grade  or  mixture  obtained,  such  as  floor  plates, 
furnace  castings  and  heavy  machinery  not  requiring 
much  finishing,  etc. ,  scrap  iron  can  often  compose  the 
greater  part  of  the  mixture,  especially  so  if  silicon  pig 
has  been  used  to  soften  the  scrap.  In  the  case  of 
stove  plate  or  light  machinery  castings  requiring  much 
finishing,  much  more  care  is  necessary  in  attempting 
to  use  much  outside  scrap  iron.  The  same  is  to  be 
said  of  chilled  work  where  definite  results  are  to  be  in- 
sured. In  many  chill  work  specialties  it  is  often  very 
poor  economy  to  adopt  the  practice  of  utilizing  any 
outside  scrap;  but,  of  course,  shop  scrap,  s,uch  as 
gates,,  etc. ,  every  shop  must  work  up  in  mixture  with 
its  pig  metal.  An  all-pig  mixture,  of  which  a  correct 
analysis  has  been  given,  enables  the  founder  to  be 
much  more  positive  in  obtaining  desired  results  than 


294  METALLURGY    OF    CAST    IRON. 

where  he  attempts  such  results  by  mixing  promiscu- 
ous scrap  with  the  pig  metal.  The  loss  of  a  few  cast- 
ings ofttimes  more  than  counterbalances  the  differ- 
ence in  the  price  of  pig  and  scrap  metal,  and  in  some 
cases,  if  the  question  of  gross  tons  in  pig  metal  is  con- 
sidered,  the  difference  will  be  found  strongly  in  favor 
of  the  straight  pig  mixture,  as  against  that  of  a  com- 
bination of  scrap,  which  is  generally  sold  by  net  tons. 

In  grading  scrap  that  shows  evidence  of  having  been 
chilled,  such  as  that  in  car  wheels,  rolls,  dies,  crushers, 
plows,  etc. ,  it  is  as  essential  to  consider  the  texture  of 
the  grey  body  of  the  casting  or  scrap  as  it  is  that  of 
the  depth  of  the  chill,  for  the  reason  that  the  depth  of 
the  chill  part  can  be  deceptive  in  denoting  the  true 
grade  of  the  iron,  from  the  fact  that  degrees  in  the 
pouring  temperature  of  metal,  as  well  as  the  thickness 
cf  the  chill  to  the  limit  used  for  forming  the  chill  part 
of  the  casting,  has  an  effect  in  forming  the  depth  of  the 
chill,  factors  more  clearly  defined  in  Chapters  XLI. 
and  LVL* 

About  the  worst  class  of  scrap  to  pass  judgment 
upon,  in  an  effort  to  grade  it,  is  that  ccming  under  the 
head  of  ' '  white  iron. ' '  Where  bodies  of  scrap  are  all 
white,  the  silicon  contents  may,  in  castings  say  from 
"  stove  plate  "  up  to  two  inches  thick,  contain  silicon 
all  the  way  from  .50  up  to  1.50,  and  in  more  massive 
castings  than  three  inches  thick,  it  is  generally  safe  to 
conclude  that  the  silicon  can  range  from  .10  up  to  0.40, 
with  sulphur  in  any  of  these  thicknesses  ranging  all 
the  way  from  .050  up  to  .200.  As  a  basis  to  guide  the 
founder  in  an  effort  to  grade  such  irons  for  mixture 
with  softer  metals,  it  can  be  taken  for  granted  that 
the  sulphur  is  generally  very  high  and  the  silicon  low 

*  For  a  discovery  showing  that  chilled  parts  give  a  softer  re-melt 
than  gray  parts  of  the  same  casting,  see  pages  338  and  339. 


MIXING    AND    MELTING    SCRAP    IRON.  295 

in  all  white  scrap    iron   as  it  comes  to  the  foundry. 

Burnt  iron  can  be  said  to  be  the  most  undesirable 
class  of  scrap  for  a  founder  to  handle,  and  there  is  a 
doubt  in  the  author's  mind  that  it  pays  any  founder  in 
the  end  to  experiment  with  it,  for  making  anything 
other  than  castings  like  sash  weights,  for,  as  a  general 
thing,  its  loss  in  weight  by  re-melting  will  range  all  the 
way  from  30  to  95  per  cent.  It  is  a  very  indefinite 
quality  to  judge  of  as  to  its  chemical  composition. 
It  is  safe  to  say  it  will  greatly  injure  other  irons  when 
mixed  with  them  in  raising  the  sulphur  and  lowering 
the  silicon  so  as  to  produce  a  ' '  white  iron, ' '  and  can 
often  spoil  many  castings. 

Any  intelligent  foundry  laborer  should,  with  a  little 
training,  be  able  to  select  and  pile  scrap  according  to 
its  grade.  As  some  would  prefer  an  approximation  for 
the  silicon  and  sulphur  contents  of  grey  scrap,  the  au- 
thor would  say  that  iron  ranging  from  stove  plate  up 
to  one  inch  in  thickness  may  be  considered  as  an  ap- 
proximate equivalent  to  remelted  pig  metal  that  has 
its  silicon  ranging  from  1.50  up  to  2.00  per  cent.,  and 
for  bodies  above  one  inch  thick  up  to  three  inches 
thick  from  i.oo  up  to  1.75  in  silicon,  sulphur  in  all 
cases  to  be  considered  as  constant  at  about  .07,  Above 
three  inches  in  thickness  a  grey  open  fracture  can  range 
in  silicon  all  the  way  from .  75  up  to  2. 50,  and  the  grading 
of  such  heavy  bodies  generally  requires  a  more  skilled 
eye  than  with  scrap,  which  might  be  under  three  inch- 
es in  thickness;  but  practice  would  soon  bring  one 
to  an  approximately  close  guessing  of  the  grade  of 
heavy,  as  well  as  light  bodies.  Where  scrap  comes 
to  the  foundry  yard  in  the  form  of  complete  castings, 
which  the  founder  will  have  to  break,  he  can,  by  *  *  siz- 


296  METALLURGY    OF    CAST    IRON. 

ing  up  ' '  the  general  proportion  and  shape  of  the  whole 
casting,  judge  more  readily  of  the  ' '  grade  ' '  in  the 
massive  parts  than  if  it  came  to  his  yard  in  a  hap- 
hazard form. 

We  are  compelled  to  analyze  pig  metal  (as  shown  on 
page  178)  simply  because  it  is  deceptive  in  showing  its 
true  *  *  grade  ' '  to  the  certainty  that  scrap  iron  will 
permit,  on  account  of  its  being  a  re-melted  product. 
If  one  wishes  to  grade  scrap  by  the  plan  suggested  on 
pages  292  to  294,  in  this  chapter,  it  is  best  to  follow 
a  silicon  formula  for  a  base,  owing  to  the  fact  that 
silicon  is  the  element  generally  largest  in  gray  castings 
excepting  carbon  and  affords  a  larger  range  or  margin 
in  guessing  percentages,  which  if  not  close  to  the 
actual  silicon  contents  cannot  so  greatly  result  in  injury 
as  it  could  if  one  used  a  guess  of  the  sulphur  for  a 
base,  and  should  err  much.  As  scrap  with  many 
founders  constitutes  a  third  and  often  two-thirds  of 
their  total  mixture,  this  chapter  cannot  but  be  of 
benefit  to  any  who  may  be  desirous  of  conducting 
their  mixtures  of  scrap  iron  with  the  best  assurance  of 
obtaining  desired  results  without  resorting  to  analysis. 

Much  oxide  of  iron,  or  rust  on  scrap  iron,  is  very 
injurious  in  lowering  the  silicon  of  a  mixture  and  thus 
cause  a  hard  iron  where  a  soft  one  was  expected. 
Burnt  annealing  boxes,  old  grate  bars,  etc. ,  give  off  a 
great  deal  of  oxide  of  iron.  The  good  iron  melts  more 
readily  than  the  oxide  of  iron.  If  any  of  the  latter  is 
not  reduced  to  iron  and  is  carried  with  the  molten 
metal  into  castings,  as  it  may  be,  blow  holes  may  be 
formed  which  are  generally  to  be  found  in  the  top  sur- 
face of  castings  as  they  are  poured.  Where  there  is  any 
apprehension  of  such  difficulty,  it  is  often  well  to  add 


MIXING    AND    MELTING    SCRAP    IRON.  297 

a  little  ferro-manganese  to  the  molten  metal.  This 
will  greatly  combine  with  the  oxide  and  come  to  the 
surface  as  slag,  which  can  be  skimmed  off.  Oxide  of 
iron  combines  readily  with  silica,  and  for  this  reason 
when  there  is  any  rust  on  scrap,  or  old  iron,  it  is  often 
desirable  to  have  some  sand  (which  is  silica)  on  pig 
iron,  that  it  may  be  charged  with  the  scrap  iron  to  assist 
in  forming  a  slag  to  be  carried  off  by  fluxing.  This 
will  greatly  absorb  the  oxide  and  give  a  cleaner  iron 
for  pouring  castings. 

The  oxide  of  iron  caused  by  the  oxidation  created  by 
the  blast,  in  the  case  of  strictly  clean  iron,  may  at  times 
be  insufficient  for  the  amount  of  sand  on  pig  iron,  etc. , 
to  form  the  right  combination  for  making  a  good 
fusible,  or  thin  slag,  to  carry  off  the  ash  of  the  fuel 
and  other  dirt  out  of  the  cupola.  In  such  cases  an 
addition  of  rusty  scrap,  etc.,  may  sometimes  work 
well.  However,  it  would  be  better  to  add  limestone 
or  other  flux  to  make  a  fusible  slag  than  to  increase 
the  oxide  of  iron  or  rust,  etc. ,  in  a  cupola.  In  cases 
of  excessive  oxide  of  iron  being  present,  it  is  abso- 
lutely necessary  to  use  limestone  or  other  flux  in 
order  to  make  a  good  slag.  It  is  claimed  that  high 
cupolas  may  have  a  reducing  action  on  oxide  of  iron, 
so  as  to  obtain  more  metal  from  rusty  scrap,  etc. ,  than 
low  cupolas.  High  cupolas  should  at  least  cause  a 
greater  loosening  than  low  cupolas  of  the  scale  from 
iron,  and  often  permit  more  of  it  being  blown  out  of 
the  stack  to  remove  some  of  its  evils.  However,  in 
striving  to  obtain  very  soft  or  clean  castings,  rusty  or 
burnt  scrap  of  all  kinds  is  best  avoided  where  practi- 
cal. 


CHAPTER  XLIV. 

CHEMICAL   CONSTRUCTION 

AND   STRENGTH    OF  TYPICAL  FOUNDRY 

IRON  MIXTURES. 

The  chemical  construction  and  highest  strength  of 

all  the  prominent  mixtures  now  being  used  in  general 
founding,  as  obtained  by  the  author  for  this  work  to  il- 
lustrate in  a  concise  and  accurate  manner  true  analyses 
of  mixtures  actually  used  by  our  leading  fotmders,  are 
shown  in  Tables  60  and  61.  The  specimens  analyzed 
are  taken  from  the  respective  tests  described  in  Chapter 
LX.  The  determinations  were  made  by  the  able  and 
careful  chemist,  Mr.  W.  A.  Barrows,  Jr.,  of  Sharps- 
ville,  Pa. : 

Analyses  Nos.  i  and  2  are  obtained  from  "  air  fur- 
nace "  iron  and  those  of  Nos.  3,  4,  5,  6  and  7  from 
cupola  iron.  A  peculiarity  which  will  attract  the  at- 
tention of  those  making  a  study  of  the  following  Table 
is  that  of  the  combined  carbon  being  so  high,  with  low 
sulphur  and  the  silicon  not  far  from  i.oo  per  cent,  in 
analyses  Nos.  i  and  2.  This  illustrates  the  benefit  derived 
from  melting  iron  in  an  "  air  furnace,"  where  it  is  not 
brought  in  contact  with  the  fuel  to  so  radically  chr^ge 
the  character  of  iron,  and  clearly  demonstrates  the 
superiority  of  the  '4  air  furnace  '  over  the  cupola  to  re- 
fine or  obtain  the  best  strength  possible  in  cast  iron. 


mf  WF 

I  WNfVjr 

X?*'  , 

^NS>       200 


ANALYSES    AND    STRENGTH    OF    TYPICAL    IRONS>^     299 

The  author  has  not  seen  any  analysis  of  cupola  iron 
showing  the  combination  of  high  combined  carbon  and 
silicon  with  the  low  sulphur  shown  in  analyses  Nos.  i 
and  2.  If  any  can  closely  duplicate  such  a  combination 
of  metalloids  by  cupola  iron  they  should  obtain  about 
the  same  results  in  strength  derived  from  the  air  fur- 
nace meltings.  This  may  be  closely  approximated, 
but  the  uncertainty  of  cupola  workings,  on  account  of 
the  iron  being  in  contact  with  fuel  and  blast,  makes  it 
a  difficult  and  a  very  unreliable  method  to  adopt. 

The  state  of  the  combined  and  graphitic  carbon  is 
the  final  resultant  of  the  combined  effects  of  all  the 
other  metalloids  and  chiefly  defines  what  character  the 
physical  qualities  will  assume,  as  regards  the  strength, 
deflection,  contraction,  and  chill  of  an  iron,  f 

TABLE   60. — CHEMICAL    ANALYSES    OF    SPECIALTY    MIXTURES    IN 

CAST    IRON.* 
Arranged  according  to  degrees  in  strength. 


No.  of 
Analysis. 

Specialty 
Mixture. 

Sil. 

Snip.      Phos. 

Mang. 

Graph. 
Carbon 

Comb. 
Carbon 

Total 
Carbon 

i 

Gun 

Metal. 

1.19 

.055          .408 

.420 

2.050 

1.130 

3  180 

2 

Chill 
Roll. 

•7i 

•058          -543 

•390 

1.620 

1-330 

3.000 

3 

Car 
Wheel. 

.86 

.127          .348 

.490 

2550 

.920 

3470 

4 

Heavy 
Machinery 

1.05 

.no          .543 

•350 

2.650 

•330 

2.98  ) 

5 

Light 
Machinery 

1.83 

.078          .504 

.310 

2  500 

•43° 

2.930 

6 

Stove 
Plate. 

2-59 

.072          .622 

•37° 

2.950 

•35  ~> 

3300 

7 

Sash 
Weight. 

.18 

.138          .094 

-350 

.150 

2.940 

3.090 

*Nos.  i  and  2  are  charcoal  irons. 


t  The  rate  of  cooling  is  also  to  be  considered  in  connection  with 
the  effects  of  the  metalloids. 


3oo 


METALLURGY    OF    CAST    IRON. 


Iron  of  the  analysis  shown  in  gun  metal  can,  in 
castings  three  inches  thick  and  over,  be  readily  ma- 
chined and  with  greater  ease  than  that  composing  the 
chill  roll  mixture.  Next  in  hardness  to  the  roll  iron  is 
the  car  wheel  metal,  the  other  specialties  following  in 
degrees  of  softness  in  the  order  shown,  until  sash 
weight  iron  is  reached,  which  specialty  excels  all 
shown  for  being  a  hard  metal  as  such  is  strictly  a 
"  white  iron."  The  following  Table  is  a  summary  of 
the  best  strength  obtained  from  a  series  of  about  100 
tests  taken  with  bars  one  and  one-eighth  inches  in 
diameter,  twelve  inches  between  supports,  in  obtaining 
the  transverse  strength,  more  fully  described  in  Chap- 
ter LX.  A  column  is  also  given  showing  the  tensile 
strength  of  all  these  specialties. 

TABLE   6l. — SUMMARY   OF   TYPICAL   AMERICAN    FOUNDRY    IRON   TESTS. 
Taken  with  one  square  inch  area  test  bars. 


Specialties  of  Mixtures. 

Transverse 
strength  per 
square  inch. 

Tensile 
strength  per 
square  inch. 

Gun  Metal 

3  686 

V7  IIO 

Chill  Roll 

•7Q  66  1 

Car  Wheel  

2  819 

25  782 

Heavy  Machinery                                      .  ... 

2  7QI 

2S  7QQ 

Light  Machinery                

2.II5 

20,655 

Stove  Plate 

i  SM 

12  582 

Sash  Weight  

1,480 

'          7,044 

The  Table  61  is  no  discredit  to  American  foundry- 
men.  It  displays  to  the  world  typical  irons  challeng- 
ing competition  in  excellence  for  the  various  special- 
ties shown. 

Ductile  cast  iron  is  the  term  applied  to  a  product 
that  was  manufactured  by  the  East  Chicago  Foundry 
Co.,  for  which  a  tensile  strength  of  50,000  to  60,000 
pounds  per  square  inch  is  claimed.  The  author  has 


ANALYSES    AND    STRENGTH    OF    TYPICAL    IRONS.        301 

•  . 

endeavored  to  obtain  all  partictilars  connected  with  its 
manufacture,  but  found  the  process  one  of  which  the 
manufacturers  did  not  care  to  impart  any  knowledge. 
This  was  in  1897,  but  at  this  time — 1902 — as  far  as  can 
be  learned,  the  manufacture  of  this  metal  has  ceased. 
To  obtain  a  knowledge  of  the  strength  of  other  metals 
in  comparison  to  cast  iron,  see  Table  137,  page  594. 


CHAPTER  XLV. 


EFFECT    OF    FUEL,    FLUXES,    TEMPERA- 
TURE  AND    HUMIDITY    OF    BLAST 
IN  RE-MELTING  CAST  IRON. 

It  is  as  important  to  possess  knowledge  of  changes 
caused  by  re-melting  iron  as  it  is  to  know  the  chemical 
constituents  of  the  iron  before  it  is  charged  into  the 
cupola.  For  the  past  seven  years  the  author  has  fol- 
lowed closely  the  records  which  were  daily  compiled 
at  our  foundry  of  the  chemical  properties  in  the  iron 
charged  and  also  the  product  received  from  the  cupola 
in  "  heats  "  ranging  from  40  to  TOO  tons.  The  follow- 
ing Table,  No.  62,  compiled  from  one  week's  melting 
in  this  foundry,  with  coke  .80  to  i.oo  in  sulphur,  will 
serve  to  illustrate  the  change  due  to  silicon  and  sulphur 
in  re-melting  iron: 

TABLE  62. — DECREASE   IN   SILICON,    AND    INCREASE   IN   SULPHUR,    BY 
RE-MELTING    IRON. 


Silicon 
in  pig. 

Sulphur 
in  pig 

Silicon 
in  castings. 

Sulphur 
in  castings. 

Loss  in 
silicon. 

Gain  in 
sulphur. 

193 

.022 

1.77 

.040 

.16 

.018 

1.84 

.016 

1.65 

.046 

.19 

.030 

1.78 

.031 

1.58 

.056 

.20 

.025 

1-52 

.029 

139 

.061 

•13 

.032 

1.46 

.027 

J-33 

.056 

•13 

.029 

1.28 

.021 

1.  10 

.067 

.18 

.046 

The  increase  in  sulphur  in  re-melting  is  dependent 


EFFECT  OF  FUEL,  FLUXES,  TEMPERATURE,  ETC.   303 

upon  the  amount  of  sulphur  in  the  fuel,  the  silicon 
and  manganese  in  the  iron,  the  flux  and  the  heat  in 
the  cupola.  An  increase  of  the  sulphur  in  the  fuel  or 
flux  will  cause  a  corresponding  increase  of  sulphur  in 
the  iron;  while  the  less  fuel  used  and  the  better  a 
cupola  is  fluxed  or  ' '  hot  iron  ' '  produced,  the  less  sul- 
phur will  the  re-melted  iron  contain. 

The  reduction  or  oxidation  of  silicon  is  greater  the 
higher  the  blast  pressure  and  also  the  hotter  the  iron 
is  melted.  In  a  general  way,  it  can  be  said  that  sili- 
con is  reduced  from  one  to  three-tenths  of  one  per 
cent,  and  sulphur  increased  from  one  to  six  hun- 
dredths  of  one  per  cent.,  where  the  fuel  holds  .80  to 
i. oo  in  sulphur.  The  author  has,  in  a  few  rare  cases, 
found  the  silicon  to  be  but  very  little  reduced,  but 
never  found  a  re-melt  where  the  sulphur  was  not 
materially  increased.  The  increase  of  one  point  of 
sulphur  can  often  neutralize  the  effect  of  ten  to  fifteen 
points  of  silicon,  and  hence,  owing  to  the  increase  of 
sulphur  being  so  powerful  in  neutralizing  the  effects 
of  silicon,  it  is  very  essential  that  all  conditions  influ- 
encing the  increase  of  sulphur  should  be  guarded  and 
controlled  so  far  as  practical,  in  order  to  be  best  as- 
sured of  obtaining  any  desired  results  in  the  castings. 

The  changes  due  to  manganese  in  re-melting  iron 
are  toward  its  reduction.  The  hotter  the  metal,  the 
higher  the  blast,  the  greater  its  reduction.  The 
reduction  can  range  from  10  to  30  points.  The  more 
manganese  iron  contains,  the  less  the  increase  of 
sulphur,  owing  to  the  affinity  manganese  possesses  for 
carrying  off  sulphur  in  the  slag. 

Phosphorus  may  be  called  a  '  *  sticker, ' '  as  when 
once  absorbed  by  iron  it  cannot  be  easily  eliminated. 


304  METALLURGY    OF    CAST    IRON. 

In  re -melting  iron,  whatever  phosphorus  the  fuel  or 
flux  may  contain  will  largely  go  to  the  iron,  and  hence 
phosphorus  has  a  tendency  to  be  increased  every  time 
iron  is  re -melted.  Its  influence  in  effecting  changes  in 
the  other  elements  is  to  favor  the  reduction  of  silicon, 
sulphur  and  manganese,  owing  to  the  quality  of  phos- 
phorus which  causes  iron  to  have  greater  fluidity  and  life. 

Total  carbon  is,  as  a  general  thing,  increased  by 
re-melting.  The  amount  is  chiefly  dependent  upon  the 
percentage  of  fuel  used,  and  the  length  of  time  the  iron 
is  in  the  cupola.  Little  fuel  and  quick  melting  may 
at  times  cause  a  slight  reduction  of  the  carbon.  In 
the  case  of  excessive  fuel  which  can  give  hot  iron  and 
cause  slow  melting  carbon  may  be  increased.  It  is 
also,  to  some  degree,  dependent  upon  the  silicon  and 
manganese  present.  The  former  retards,  while  the 
latter  promotes  the  increase  of  carbon. 

Combined  carbon  with  the  silicon  above  four  per 
cent.,  and  sulphur  not  over  .01,  may  sometimes  be 
slightly  reduced.  After  silicon  has  decreased  to 
4.00  with  the  sulphur  above  .02,  every  re-melt  will 
surely  increase  the  combined  carbon  until  the  silicon 
is  so  decreased  and  the  sulphur  increased  that  ' '  white 
iron"  will  be  produced,  giving  an  iron  which  may  have 
its  carbon  almost  wholly  in  a  combined  form. 

Graphitic  carbon  is  increased  accordingly  as  combined 
carbon  is  decreased,  and  the  elements  best  calculated 
to  promote  its  formation  are  silicon  about  3.50  and 
phosphorus  not  above  1.25,  with  low  sulphur. 

In  a  general  way  it  can  be  said  that  with  iron 
melted  in  the  cupola,  the  silicon,  manganese  and 
graphitic  carbon  are  decreased,  while  the  sulphur, 
phosphorus  and  combined  carbon  are  increased. 


EFFECT  OF  FUEL,  FLUXES,  TEMPERATURE,  ETC.   305 

In  connection  with  a  study  of  this  chapter,  readers 
•are  referred  to  tests  showing  losses  of  silicon  and  man- 
ganese, and  gains  in  sulphur,  phosphorus,  and  carbon 
found  in  Tables  73  and  76,  pages  334  and  341.  It  is  to  be 
understood  that  the  foregoing  pages  of  this  chapter  deal 
with  cupola  practice  only ;  and  as  the  author  has  had 
no  opportunity  of  late  for  experimenting  with  results 
to  be  derived  from  re-melting  iron  in  an  "  air  furnace, ' 
he  cites  the  following  extract  from  Sir  William  Fair- 
bairn's  report  before  the  British  Association  of  Science 
on  the  effect  of  re-melting  iron  in  an  "  air  furnace  " 
eighteen  times,  in  which  he  describes  the  action  of  re- 
melting  as  follows: 

Phosphorus  increased  from  0.47  to  0.61.  This  was  probably 
due  to  loss  of  metal  by  oxidation.  Manganese  decreased  from 
1.75  to  .12.  This  would  tend  to  improve  the  metal  during  the 
earlier  meltings.  Silicon  was  reduced  from  4.22  to  1.88.  The 
first  effect  of  this  reduction  was  to  produce  softer  metal  and 
lower  combined  carbon,  since  silicon  was  present  in  quantity  in  ex- 
cess of  that  necessary  for  the  softest  metal.  On  further  reduction 
of  silicon  the  metal  became  stronger  and  harder.  But  in  these  ex- 
periments the  reduction  was  not  carried  sufficiently  far  to  cause 
any  deterioration  due  to  sufficiency  of  silicon.  Sulphur  in- 
creased from  .03  to  .20,  and  this  is  one  of  the  most  important 
changes  which  took  place,  the  increase  in  sulphur  tending  in  the 
same  direction  as  the  loss  of  silicon,  viz.,  the  production  of  high 
combined  carbon.  The  combined  carbon  increased  considerably 
after  the  eighth  melting,  ultimately  reaching  to  over  two  per  cent. 

By  Fairbairn's  experiments  we  find  that  the  results 
of  re-melting  in  an  air  furnace  are  in  part  similar  to 
those  of  a  cupola,  and  in  both  cases  it  is  a  subject  as 
necessary  to  be  understood,  in  order  to  obtain  desired 
ends,  as  is  that  of  knowing  the  chemical  properties  of 
the  iron  before  it  is  charged. 

There  have  been  experiments  conducted  in  order  to 


306  METALLURGY    OF    CAST    IRON. 

observe  whether  there  would  be  any  difference  in  the 
strength  of  iron  taken  from  the  beginning,  middle, 
and  end  of  "heats,"  where  a  uniform  mixture  was 
used  throughout  a  heat.  Results  received  affirm  that 
some  would  obtain  the  strongest  test  at  one  part, 
while  others  would  receive  them  from  another  part  of 
a  heat.  In  this  practice  the  author  cannot  conceive 
of  any  uniformity  being  obtained  unless  the  manage- 
ment is  such  as  to  insure  a  like  temperature  and  flux- 
ing at  every  part  of  a  "  heat,"  and  in  this  quality  gen- 
erally lies  the  secret  of  the  difference  between  one 
founder  and  another.  One  may  have  a  cupola  giving 
the  hottest  iron  at  the  beginning  of  a  heat  while 
another  will  obtain  this  at  the  middle  or  the  end. 
According  to  the  variation  of  temperature  when  re- 
melting  iron,  so  is  the  combined  carbon  affected  by 
changes  in  the  silicon,  sulphur  and  manganese ;  and 
taking  this  view  of  the  subject  the  author  believes  that 
all  can  understand  why  we  find  founders  disagreeing 
in  such  tests. 

As  the  humidity  of  the  air  can,  to  some  extent,  pro- 
duce changes  in  the  smelting  or  melting  of  iron,  one 
heat  from  another,  the  author  appends  the  following 
excellent  article  written  by  Mr.  A.  Sorge,  Jr.,  M.  E., 
in  the  Foundry,  April,  1896: 

That  variations  in  the  humidity  of  the  atmosphere  and  its  tem- 
perature do  affect  the  -operation  of  melting  iron  in  a  cupola,  will 
be  conceded  t?y  foundrymen  who  have  observed  the  difference  in 
melted  iron  on  different  days.  Iron  is  liable  to  be  cold  and  slug- 
gish with  the  same  charges  of  fuel  on  cold  and  moist  days,  while 
it  is  hot  and  fluid  on  warm  and  bright  days. 

It  is  therefore  reasonable  to  look  for  one  cause  of  poor  melting 
to  the  atmospheric  conditions.  Let  us  assume  that  we  are  melt- 
ing at  a  ratio  of  eight  iron  to  one  coke  on  an  ordinary  bright  day, 


EFFECT    OF    FUEL,    FLUXES,   TEMPERATURE,   ETC.      307 

when  the  temperature  is  62  degrees  F. ,  and  the  percentage  of 
moisture  in  the  atmosphere  about  0.52  per  cent.,  which  is  about 
the  average  in  Chicago. 

It  has  been  found  by  experience  that  about  33,000  cubic  feet  of 
air  are  required  to  melt  2,000  pounds  of  iron  in  ordinary  cupola 
practice.  This  air  will  weigh  about  2,500  pounds,  and  is  heated 
originally  to  a  high  temperature  by  the  ignited  coke  before  it  be- 
comes active  in  supporting  further  combustion.  Also  any  mois- 
ture contained  in  this  air  must  be  brought  to  the  temperature  of 
the  gases  which  escape  from  the  top  of  the  cupola.  This  latter 
temperature  varies  greatly,  but  will  be  in  the  vicinity  of  500  de- 
grees F.  for  good  practice. 

If  the  temperature  of  the  atmosphere  should  drop  to  32  de- 
grees F. ,  this  means  that  the  air  delivered  to  the  cupola  must  be 
heated  30  degrees,  so  as  to  bring  it  to  the  normal.  The  specific 
heat  of  air  being  taken  at  0.238,  we  obtain  2,500  X  30  X  0.238  = 
17,850  B.  T.  U.  as  the  amount  of  heat  required  to  do  this  work, 
or  theoretically  about  i^  pounds  coke  would  be  consumed  if  we 
obtained  perfect  combustion.  The  fact  being  that  the  actual 
amount  of  heat  obtained  from  the  combustion  of  coke  in  a  cupola 
is  only  about  ^  of  the  theoretical,  it  follows  that  the  actual  coke 
consumed  for  this  extra  heating  is  about  5^  pounds,  which  should 
be  added  to  the  usual  amount  of  250  pounds  per  ton  of  iron,  mak- 
ing 255^  pounds, -or  a  ratio  of  about  7.8  iron  to  i  coke. 

If,  at  the  same  time,  the  air  is  charged  with  particles  of  mois- 
ture, as  when  a  heavy  snow-storm  is  in  progress,  it  will  contain, 
say,  about  4-10  per  cent,  of  frozen  water.  In  the  2,500  pounds 
total  this  will  amount  to  10  pounds,  which  must  be  transformed 
into  vapor  at  500  degrees  F.,  involving  14,740  B.  T.  U.  of  heat. 
On  the  other  hand,  this  amount  is  reduced  by  the  heat  expended 
in  raising  the  average  vapor  of  0.52  per  cent,  in  62  degrees  air  to 
500  degrees  F.,  which  amounts  to  2,714  B.  T.  U.,  leaving  an  extra 
amount  of  12,036  B.  T.  U.  consumed  by  the  snow,  which  will 
again  require  about  3.6  pounds  coke. 

The  total  coke  consumption  in  the  above  case  will  therefore  be 
259.1  pounds  per  ton  of  iron,  or  a  ratio  of  7.7  iron  to  i  coke,  in 
order  to  deliver  the  melted  iron  in  the  same  condition  as  on  an 
ordinary  day.  In  other  words,  an  additional  fuel  consumption 
of  a  little  over  3.6  per  cent,  is  needed  under  the  above  conditions, 


308  METALLURGY    OF    CAST    IRON. 

so  as  to  obtain  the  iron  in  the  same  state  of  heat  and  fluidity  as 
when  ordinary  dry  air  at  62  degrees  is  used. 

On  the  other  hand,  a  higher  temperature  and  greater  dryness 
of  the  atmosphere  will  operate  in  permitting  the  amount  of  fuel 
to  be  reduced. 

In  the  above  figures  I  have  assumed  ordinary  conditions,  but 
the  actual  practice  must  be  carefully  taken  into  consideration 
wherever  it  is  desired  to  figure  out  the  effects  in  any  particular 
case,  and  it  is  well  worth  a  foundryman's  time  to  go  into  this 
question,  figuring  out  the  extra  amounts  of  coke  needed  under 
various  conditions  of  moisture  and  temperature,  when  a  short 
observation  of  an  ordinary  hygrometer  and  thermometer  will 
enable  him  to  avoid  the  risk  of  cold  and  sluggish  metal  on  any 
day. 

Mr.  W.  H.  Fryer  has  shown  and  published  the 
"statement*  that  air  containing  0.8  per  cent,  of  mois- 
ture will  introduce  about  89.6  pounds  of  water  into  a 
blast  furnace  per  ton  of  iron  made,  using  about  2,250 
tons  of  coke  for  fuel.  This  is  a  factor  the  founder 
should  not  lose  sight  of.  When  air  is  moist,  it  is  to 
some  degree  practically  the  same  thing  as  fuel  being 
water-logged.  With  very  wet  fuel,  as  many  founders 
kriow,  a  larger  percentage  is  necessary  to  re-melt  iron 
than  if  the  fuel  were  perfectly  dry,  and  also  that  this 
can  cause  trouble  much  more  readily  in  the  line  of 
"  bunging  up  "  a  cupola.  For  further  information  of 
the  effects  of  humidity,  see  Chapters  IX.  and  X. 
*  Journal  of  the  Iron  and  Steel  Institute,  Vol.  II.,  1887. 


CHAPTER  XLVI. 

LOSS  OF  IRON  BY  OXIDATION  IN 
CUPOLAS.* 

The  amount  of  iron  lost  by  melting  is  as  important 
an  item  for  consideration  as  that  of  any  other  material 
necessarily  destroyed  in  the  making  of  castings. 
Many  founders  endeavor  to  keep  a  close  record  of  such 
losses,  but  there  are  many  who  cannot.  Founders 
who  can  clean  up  each  day's  heat  of  castings  and 
collect  all  their  fine  shot,  scrap,  and  gates  the  day 
following  each  heat  are  in  the  best  position  to  obtain 
the  greatest  accuracy  in  such  records,  but  shops  where 
castings  lie  in  the  sand  from  one  to  six  days  or  more 
before  they  can  be  removed  or  cleaned  up  find  the  task 
a'  much  more  difficult  one.  In  buying  pig  iron  the 
furnaceman  allows  268  pounds  per  ton  for  scale  and 
sand  on  sand  cast  pig,  and  240  pounds  on  chilled  cast  pig. 
How  much  of  this  is  actual  refuse  is  difficult  to  deter- 
mine accurately.  When  first  studying  the  method  of 
casting  pig  metal  in  chills,  the  author  could  see 
nothing  unfavorable  to  the  universal  adoption  of  metal 
so  cast  for  founders  and  steel  makers.  It  was  not  until 
at  a  meeting  of  the  Pittsburg  Foundry  men's  Associa- 
tion, December  3,  1898,  where  a  member  made  the 
claim  that  a  greater  loss  would  be  incurred  by  the  use 
of  chilled  cast  pig  iron,  in  re-melting  iron,  than  by 
having  sand  and  scale  on  it  —  which  was  said  to  afford 

*This  chapter  is  a  revised  extract  of  a  paper  presented  by  the 
author  to  the  Pittsburg  Foundry  men's  Association,  January,  1898. 


310  METALLURGY    OF    CAST    IRON. 

a  protection  to  the  iron  against  oxidation,  or  being 
burned  away  while  being  brought  to  a  liquid  state  — 
that  any  disadvantage  was  apprehended.  The  author 
has  no  knowledge  of  the  process  by  which  the  above 
member  arrived  at  his  conclusions,  and  can  only 
say  that  to  obtain  definite  proof  of  this  claim 
steps  differing  from  general  practice  in  melting  are 
necessary.  The  author,  realizing  this,  made  a  series 
of  original  tests  embodying  sixteen  heats,  made  in  the 
twin  shaft  cupola  Fig.  56,  page  241,  and  shown  in 
Tables  63  to  66.  In  making  the  comparative  oxidation 
tests  shown  in  these  tables  much  care  was  necessary  in 
preparing  the  cupola  and  collecting  its  refuse.  In  get- 
ting this  cupola  ready  (Fig.  56)  for  a  heat  both  depart- 
ments were  picked  out  and  daubed  up  ,smoothly  and 
then  blacked  over  with  graphitic  or  lead  blacking. 
Such  a  plan  insured  that  no  iron  stuck  to  the  sides  from 
the  preceding  "heats,"  to  be  melted  down  with,  or 
change  the  irons  obtained  from  the  respective  sides. 
The  bottom  was  not  dropped  after  heats,  as  in  ordinary 
practice,  but  after  the  cupola  had  cooled  down  the 
refuse  was  picked  out  from  the  top  downward  by  hand, 
and  every  particle  carefully  pounded  in  a  pan  to  dis- 
cover any  fine  shot  or  pieces  of  scrap  that  might 
exist  in  the  burnt  coke,  dross,  or  slag  remaining  in  the 
cupola  at  the  close  of  a  heat.  This  was  then  weighed 
on  fine  scales.  By  this  plan  not  a  single  ounce  of  metal 
that  remained  as  such  could  escape  being  found. 

Heats  Nos.  i  and  2,  Table  63,  were  charged  with 
rolls  that  were  cast  from  the  same  ladle,  half  being 
made  in  sand  and  half  in  chill  molds,  such  as  seen  at 
Fig.  59.  The  roll  castings  were  after  the  pattern  seen 
in  Fig.  58,  which  it  may  be  said  was  the  same  form  in 


LOSS    OF    IRON    BY    OXIDATION    IN    CUPOLAS. 


which  the  iron  was  charged  in  heats  Nos.  3,  4,  5,  6,  7, 
and  8,  as  well  as  those  shown  in  Tables  65  and  66, 
where  rolls  are  cited.  The  loss  from  heats  Nos.  i  and 
2  ran  about  5  per  cent,  for  the  sand  rolls  and  3  per 
cent,  for  the  chilled  iron.  When  the  first  two  heats 
are  compared  with  those  of  the  chilled  iron  by  the 

TABLE   63. — COMPARATIVE   OXIDATION   TESTS   OF   PROTECTED   AND 
UNPROTECTED   IRON    SURFACES. 


Heat 
No.  i. 

Heat 
No.  2. 

Heat 
No.  3. 

Heat 

No.  4. 

Heat 
No.  5. 

Heat 
No.  6. 

Heat 
No.  7. 

Heat 
No.  8. 

Kind  of  Metal 
Charged. 

Sand  and 
Chill  Rolls. 

Sand  and 
Chill  Rolls. 

Chill  Rolls. 

Chill  Rolls. 

Chill  Rolls. 

Chill  Rolls. 

Chill  Rolls. 

Chill  Rolls. 

Kind  of  protec- 
tion    used    on 
coated  rolls... 

Sand 
Scale. 

• 
Sand 
Scale. 

Lead 
Wash. 

Lead 
Wash. 

Lime 
Wash. 

Lime 
Wash. 

Sit 

Soda. 

Sil. 
Soda. 

Weight    of    un- 
protected   and 
protect  ed 
charges  

H4lbs. 

80  Ibs. 

84  Ibs. 

54  Ibs. 

8  1  Ibs. 

85  Ibs. 

78  Ibs. 

90  Ibs. 

Blast  put  on  

3.36 

3-i8 

3-47 

2.20 

3-17 

2-54 

3-04 

3-43 

Protected    iron 
running  

3-44K 

3.27* 

3-53K 

2.27 

3-25 

3-oofc 

3-09K 

3-52* 

Unprotec  ted 
iron  running... 

3-43 

3  --5 

3.52$* 

2.26 

3-23K 

3-oo 

3-09 

3-52 

Protected    iron 
all  down  

4-035* 

3.40 

4-03% 

2.34^ 

3-37^ 

3."$* 

3-20 

4-o7# 

Unprotected 
iron  all  down.. 

4.01 

3-37^ 

4.02 

2.33# 

3-37 

3."# 

3-I9K 

4.06 

Weight  of  pro- 
tected iron  ob- 
tained   

108  Ibs. 
3oz. 

75  Ibs. 

2  OZ. 

8  1  Ibs. 

I  OZ. 

52  Ibs. 

I  OZ. 

77  Ibs. 
13  oz. 

81  Ibs. 
15  oz. 

75  Ibs. 

II  OZ. 

87  Ibs. 
8oz. 

Weight   of   un- 
protected iron 
obtained  

1  10  Ibs. 

2  OZ. 

77  Ibs. 

2OZ. 

81  Ibs. 

I  OZ. 

52  Ibs. 
3oz. 

78  Ibs. 
3oz. 

8  1  Ibs. 
14  oz. 

75  Ibs. 

12  OZ. 

87  Ibs. 
6oz. 

LOSS  of  protect- 
ed iron  

5  Ibs. 
1302. 

4  Ibs. 
14  oz. 

2  Ibs. 
15  oz. 

lib. 
15  oz. 

3  Ibs. 
302. 

3  Ibs. 

I  OZ. 

2  Ibs. 
SQZ. 

2  Ibs. 
8oz. 

LOSS  of   unpro- 
tected iron  

3  Ibs. 
14  oz. 

2  Ibs. 
14  oz. 

2  Ibs. 
15  oz. 

lib. 
13  oz. 

3  Ibs. 

I  OZ. 

3  Ibs. 

2  OZ. 

2  Ibs. 
4oz. 

2  Ibs 

IO  OZ.' 

*  This  has  reference  to  the  sand  that  formed  a  scale  on  the  sand  cast  rolls 
and  which  were  charged  on  one  side,  while  the  chilled  rolls  were  charged  on 
the  other,  of  the  cupola,  for  heats  Nos.  i  and  2.  For  heats  Nos.  3  to  8  all  chill 
rolls  were  used  for  both  sides,  the  only  difference  being  the  chills  for  one  side 
were  coated  as  described  on  pages  313,  314  and  317. 


312 


METALLURGY    OF    CAST    IRON, 


TABLE   64. — COMPARATIVE   FUSION   TESTS   BY    IMMERSION    OF   IRONS 
SHOWN   IN   TABLE    63.       SEE    PAGE    314. 


Heat 
No.  i. 

Heat 
No.  2. 

Heat 
No.  3. 

Heat 

No.  4. 

Heat 

No.  5. 

Heat 
No.  6. 

Heat 
No.  7. 

Heat 
No.  8. 

Time  of  im- 
mersing rolls 
2%"  diameter  * 

4:00 

4:00 

4:00 

4:00 

4:00 

4:00 

4:00 

4:00 

Time  of  total 
fusion  of  sand 
protected  rolls 

4-.04K 

4:06 

4:09^ 

4:10^ 

4:06 

4:06^ 

4:04 

4:04% 

Time  of  total 
fusion  of  un- 
protected rolls 

4:03 

4»3fc 

4:02^ 

4:02% 

4:03 

4:03^ 

4:02% 

4»3tf 

Difference  i  n 
time  of  melt- 
ing   

i%m. 

2^m. 

7m. 

7%  m. 

3m. 

3tf  m. 

itfrn. 

ifcm. 

*The  time  of  dipping  was  changed  to  the  unit  of  4:00  o'clock  shown  so  as  to 
make  the  table  easier  of  solution.  The  relative  differences,  however,  were 
kept  exactly  the  same  as  originally  found. 


FIG.    58. 


FIG.   59- 


LOSS    OF    IRON    BY    OXIDATION    IN    CUPOLAS. 


313 


protected  and  unprotected  plan  seen  in  heats  Nos.  3  to 
8,  it  will  appear  how  unreliable  are  the  data  as  to  how 
much  sand  or  scale  one  is  crediting  to  iron  when 
weighing  the  charges  of  sand-coated  pig  irons  for 
regular  cupola  practice.  To  avoid  this  uncertainty,  I 
adopted  the  idea  of  taking  gray  iron  cast  in  chill 
moulds  for  both  sides  of  the  cupola,  coating  that  for 
one  side  heavily  with  some  heat  resisting  material  (by 
giving  each  three  coats  and  drying  them  in  an  oven 
after  every  coating),  and  charging  the  other  side  with 
the  surface  of  the  chilled  or  sandless  gray  iron  exposed. 
By  weighing  the  iron  before  it  was  coated  I  knew 
exactly  what  weight  of  iron  was  going  into  the  respec- 

TABLE    65. — COMPARATIVE    OXIDATION   TEST    OF    IRONS    CHARGED    ON 
HIGH    AND    LOW    BEDS   OF    FUEL.       SEE    PAGE  3! 5. 


Heat 
No.  9. 

Heat 
No.  10. 

Heat 
No.  ii. 

Heat 
No.  12. 

Kind  of  metal  charged. 

Chill  rollsun- 
protected. 

Chill  rollsun- 
protected. 

Chill  rolls 
coated  with 
lead  wash. 

Chill  rolls 
coated  with 
lead  wash. 

Weight  of  charges  each  side  

64  Ibs. 

73  Ibs. 

75  Ibs. 

zoo  Ibs. 

Blast  on  ,  

3-55 

4.27 

3-42 

3-33 

High  bed  running  

4.02 

4.38 

3-50 

345 

Low  bed  running  

4.00 

4-33^ 

3-47^ 

3-39 

High  bed  all  down..  

4-n^ 

448 

3-03M 

405 

LOW  bed  all  down 

4.08 

4.44 

4-56^ 

3-55 

Weight  of  iron  obtained  from  high  bed 

62  Ibs. 
6  oz. 

70  Ibs. 
7oz.  - 

72  Ibs. 
9  oz. 

96  Ibs. 

12  OZ. 

Weight  of  iron  obtained  from  low  bed.. 

62  Ibs. 

10  OZ. 

70  Ibs. 
8  oz. 

72  Ibs. 
14  oz. 

96  Ibs. 
14  oz. 

LOSS  of  iron  from  high  bed  

lib. 

2  Ibs. 

2  Ibs. 

3  Ibs. 

10  OZ. 

9  oz. 

7oz. 

4  oz. 

LOSS  of  iron  from  low  bed  

lib. 

2  Ibs. 

2  Ibs. 

3  Ibs. 

6  oz. 

8oz. 

2  OZ. 

2  OZ. 

tive  sides  of  the  cupola.     In  reality,  I  consider  this  the 
only  true  way  of  making  a  comparison  between  chill 


314 


METALLURGY    OF    CAST    IRON. 


and  sand-cast  pig  metals  to  judge  whether  scale  or  sand 
prevents  a  loss  of  iron  by  oxidation.'  For  heats  Nos. 
3»  4>  5>  6,  7,  and  8  all  chilled  irons  were  used,  the  only 
difference  being  that  I  used  different  materials  for 
coating  or  protecting  the  surface  of  the  chill,  or  sand- 
less  pig  rolls,  which  were  to  be  charged  as  protected 
irons.  Of  the  three  coatings  used  —  lead  wash  wet 
with  molasses  water,  lime  wash  which  was  hardened 
with  salt,  and  silicate  of  soda  —  the  lead  wash  afforded 
the  best  protection.  This  was  proven  by  the  less  time 
required  by  unprotected  chills  to  start  and  end  in  melt- 
ing than  the  chill  or  sandless  pig  rolls  having  their 
surfaces  protected  or  coated  with  the  lead  wash. 

Believing  an  immersion  test  would  furnish  a  good 
check  on  the  action  of  the  different  protectors  —  lead, 

TABLE    66. — COMPARATIVE     OXIDATION     TEST     OF     STOVE     PLATE     AND 
HEAVY    IRON.      SEE    PAGE    316. 


Heat 
No.  13. 

Heat 
No.  14. 

Heat 
No.  15. 

Heat 

No.  16. 

Kind  of  metal  charged. 

+J 

jSd 

ftd 

2 
|1 

UQrt 

Stove  plate 
and  rolls, 

tj 
a   . 
%& 

II 

^rt 

^-inch  plate 
and  rolls. 

Weight  of  charge  each  side  i 

ioo  Ibs. 

65  Ibs. 

ioo  Ibs. 

65  Ibs. 

Blaston  

3-34 

3-06 

2  20 

3-n 

Heavy  iron  running  

3-39^ 

3-12 

2.25 

3-i6tf 

Plate  running  .*.  

3-355* 

3.°7X 

2.23^ 

3-15 

Heavy  iron  all  down  

3-54 

3.21 

2.35 

3-22^ 

Plate  all  down  

3-44 

3-13 

2.33 

3-21 

Weight  of  heavy  iron  obtained  

96  Ibs. 

15  o/.. 

62  Ibs. 

II  OZ. 

97  Ibs. 

2  OZ. 

63  Ibs. 

I  OZ. 

Weight  of  plate  obtained  

89  Ibs. 

57  Ibs. 

94  Ibs. 

6  1  Ibs. 

14  oz. 

9  oz. 

5oz. 

II  OZ. 

LOSS  of  heavy  iron.               

3  Ibs. 

2  Ibs. 

2  Ibs. 

i  Ib. 

I  OZ. 

50z. 

14  oz. 

15  oz. 

LOSS  of  plate. 

10  Ibs. 

7  Ibs. 

5  Ibs. 

3  Ibs. 

2  OZ. 

7oz. 

II  OZ. 

50z. 

LOSS    OF    IRON    BY    OXIDATION    IN    CUPOLAS. 


315 


lime,  and  silicate  of  soda,  shown  in  Table  63  —  I  cast 
and  prepared  two  rolls  from  each  heat,  coating  one  and 
leaving  the  surface  of  the  other  bare,  connecting  the 
two  for  immersion  in  liquid  iron  by  a  rod  M  after  the 
plan  seen  in  Fig.  51,  page  232.  By  a  study  of 
Table  64,  one  will  perceive  that  the  chilled  rolls 
coated  with  lead  best  resist  fusion  by  immersion,  as 
well  as  the  heat  of  melting  in  the  cupola.  In  fact,  all 
the  immersion  tests  made  coincided  very  closely  with 
the  results  found  by  the  twin  shaft  cupola  experiments, 
and  strongly  confirm  the  conclusion  to  be  drawn  from 
Table  63,  page  311. 

TABLE   67. — ANALYSES    OF    SILICON    AND    MANGANESE  IN   LOW  AND 
HIGH    BED    IRONS,    OF   TABLE   6$.       SEE    PAGES    313    AND    317. 


Heat  No.  10. 

Heat  No.  n. 

Silicon. 

Man. 

Silicon. 

Man. 

Height  of  bed,  low  side.. 

1.41 
1.36 

•34 
•3i 

1.46 
1.41 

•38 
•32 

Height  of  bed,  high  side  
Difference  

•05 

•03 

•«5 

.06 

After  completing  the  tests  illustrated  in  Tables  63 
and  64,  I  thought  it  desirable  to  learn  what  difference, 
if  any,  high  and  low  beds  of  fuel  might  cause  in  losses 
of  iron.  By  referring  to  Table  65  it  will  be  seen  that 
tests  Nos.  9  and  10  were  heats  having  the  chilled  pig 
rolls  charged  without  coating,  whereas  heats  Nos.  n 
and  12  had  the  surface  of  the  iron  protected  with  a 
wash  of  lead  blacking.  In  all  these  four  heats,,  it  will 
be  seen  the  loss  was  slightly  greater  with  the  iron 
charged  on  the  high  bed,  or  that  side  using  the  most 
fuel.  While  this  is  true,  it  is  to  be  said  that  more  fine 
shot  and  scrap  was  found  in  the  side  having  the  low 


3i6 


METALLURGY    OF    CAST    IRON. 


bed.  In  general  practice,  the  chances  are  that  the 
majority  of  founders  would  not  go  to  the  labor  and 
expense  of  endeavoring  to  collect  all  this  fine  shot  and 
scrap  so  closely  as  was  done  with  these  tests.  Hence 
the  loss  of  iron  to  be  experienced  in  actual  practice  can 
be  reckoned  as  the  greatest  with  founders  aiming  to 
economize  fuel  in  an  extreme  measure,  thereby  not 
procuring  good  hot  iron.  All  experienced  founders 
know  that  high  beds  of  fuel  give  hotter  iron,  but  that 
it  melts  slower  than  iron  charged  on  low  beds.  The 
difference  in  the  heights  of  bed  coke  used  in  the  experi- 
ments in  Table  65  was  about  10  inches. 

The  four  heats  seen  in  Table  65  having  been  com- 
pleted, I  next  tested  stove  plate  iron  in  comparison  with 
the  sandless  roll  iron  as  used  in  previous  heats.  In 
selecting  the  stove  plate,  I  secured  it  as  clean  as  I 

TABLE  C8. — ANALYSES  OF  IRON  IN  SLAG  FROM  LOW  AND  HIGH  BEDS, 
STOVE  PLATE  AND  HEAVY  IRONS.   SEE  PAGE  317. 


bSS 

d 

^cj 

ti? 

°^Z 

5 

0-3  o 

"S^g 

g.2« 

o 

g.2.g 

S'"  rt 

"  0  JH 

a 

"  °ffi 

"  °ffi 

£~ 

S 

PH'" 

£•** 

Height  of  bed,  low  side  
Height  of  bed,  high  side  

31-39 
24.06 

Heavy  iron 
Stove  plate 

25.13 

23-56 

26.78 
16.97 

Difference 

7-33 

1.57 

9.81 

could,  picking  it  out  from  the  scrap  pile.  Notwith- 
standing this,  its  loss  will  be  seen,  by  referring  to 
Table  66,  tests  13  and  14,  to  exceed  by  about  7  per  cent, 
that  of  the  more  solid  heavy  iron  used  in  comparison 
with  it. 

After  testing  the  stove  plate  referred  to,  I  then  ran 
two  heats  having  a  plate  casting  ^  of  an  inch  thick, 


LOSS    OF    IRON    BY    OXIDATION    IN    CUPOLAS.  317 

broken  in  pieces  about  4  inches  square,  and  melted  it  in 
comparison  with  the  rolls  or  heavier  iron,  as  seen  in 
tests  15  and  16.  This  %-inch  plate  iron  was  cast  espe- 
cially for  the  purpose  and  used  the  day  following,  so 
that  it  was  perfectly  free  from  all  rust  or  dirt  scale,  its 
coat  being  only  that  of  the  film  of  oxide  formed  on  its 
surface  while  in  the  green  sand  mould.  The  loss  of 
this  ^ -inch  plate  will  be  seen  to  be  about  5  per  cent., 
and  this  can  be  taken  as  a  good  test  for  this  character 
of  flat-faced  surfaces,  when  charged  in  the  form  of 
clean  scrap,  not  exceeding  i  inch  in  thickness.  It 
will  be  well  to  state  that  the  iron  used  for  pouring 
the  chilled  or  sandless  gray  roll  bodies  used  through- 
out all  the  heats  herein  described  (form  shown  in  Fig. 
58)  were  taken  from  one  of  our  regular  shop  cupola 
heats  and  would  average  about  1.70  silicon,  .045 
sulphur,  .50  manganese,  and  .10  phosphorus.  .Owing 
to  this  iron  being  moderately  high  in  silicon  and  fairly 
low  in  sulphur,  it  would  only  chill  to  a  depth  of  about 
%  of  an  inch  in  the  small  rolls  shown.  Such  a  depth 
of  chill  on  the  surface  of  the  rolls  used  for  the  heats 
herein  described,  would  agree  fairly  well  with  that 
found  in  general  gray  pig  irons  that  had  been  cast  in 
chills  instead  of  sand  molds,  and  I  believe  all  will  con- 
cede it  to  be  an  iron  well  suited  for  tests  on  the  com- 
parative oxidation  of  chilled  and  sand-cast  pig  metal. 
Table  67  would  show  that  greater  silicon  and  manga- 
nese were  lost  on  the  high  beds  than  the  low  beds  of 
fuel.  Another  interesting  point,  widen  may  surprise 
many,  is  that  the  slag  which  came  from  the  stove  plate 
iron,  as  seen  in  Table  68,  has  a  less  percentage  of  iron 
in  it  than  that  which  came  from  the  heavier  or  sandless 
gray  roll  iron.  While  this  is  shown  as  such,  it  does 


318  METALLURGY    OF    CAST    IRON. 

not  imply  that  there  is  a  less  total  loss  of  iron  with 
stove  plate  than  heavier  iron,  as  we  know  by  actual 
practice  the  reverse  to  be  true.  The  greater  loss  of 
iron  by  remelting  stove  plate  than  is  found  in  heavier 
irons,  is  due  to  the  films  of  oxide,  or  scales  of  rust  and 
dirt  which,  when  attacked  by  the  high  temperatures  of 
a  cupola,  etc. ,  in  blast,  either  go  to  make  extra  slag  or 
escape  out  of  the  stack  in  other  forms.  This  phenom- 
ena in  extra  slag  production  is  exhibited  in  actual 
practice  whenever  we  melt  dirty  or  burnt  iron,  as  all 
founders  well  know. 

The  facts  presented  herewith  suggest  that  opinions 
of  the  past  in  regard  to  oxidation  of  metal  are  in  many 
cases  not  well  founded,  and  that  where  losses  of  iron 
have  been  attributed  to  oxidation  of  the  metallic  iron 
proper,  or  a  reduction  of  the  metalloids,  proper  account 
has  not  been  taken  of  the  dirt,  rust,  or  films  of  oxide 
that  might  have  covered  the  surface  of  the  pig  or  scrap 
iron  used.  We  are  led  to  conclude  that  if  it  were  pos- 
sible for  us  to  secure  clean  iron,  free  of  all  sand,  rust 
or  scales,  or  oxide  of  iron,  the  loss  of  metallic  iron  due 
to  oxidation  proper  is  not  as  large  as  has  been  generally 
supposed. 

During  the  discussion  of  this  paper,  Mr.  Uehling 
showed  the  reliability  of  the  author's  experiments  on 
oxidation  by  presenting  the  following  losses  (Table  69) 
calculated  from  the  results  given  in  Table  63,  page  311: 

TABLE   69. 

Sand  iron  lost 5-595  per  cent  average. 

Lime  wash  loss 3-7^5 

Graphite  wash  loss 3-425    " 

Chilled  iron  loss 3-395    " 

Soda  silicate  wash  loss 2.875     "       " 


LOSS    OF    IRON    BY    OXIDATION    IN    CUPOLAS.  319 

This  table,  it  was  contended,  showed  the  remarkable 
accuracy  attained  with  even  such  small  heats.  Mr. 
Uehling  in  explaining  the  reason  why  chilled  pig  would 
not  waste  as  much  as  the  sand  pig,  said  it  was  due  to 
the  fact  that  a  slight  formation  of  oxide  of  iron  in  the 
case  of  the  sand  pig  would  immediately  cause  a  slag- 
ging action,  the  iron  thus  being  absolutely  lost,  whereas 
in  a  chilled  pig  the  oxide  coming  in  contact  with  incan- 
descent carbon  fuel  would  be  reduced  back  to  iron 
again.  Here  also,  he  said,  would  come  the  advantage 
of  plenty  of  fuel  to  keep  the  flame  as  constantly  up 
to  the  reducing  action  as  possible. 

LOSS  OF  IRON  BY  SLAGGING  OUT. 

The  following  data  was  first  presented  by  the  author 
before  the  Western  Foundry  men's  Association  April 
1 8,  1894.  Iron  is  lost  by  being  carried  off  with  slag  as 
well  as  by  oxidation  in  a  cupola.  The  author  was  led 
into  an  investigation  of  this  subject  on  account  of  the 
peculiarities  in  slag  foaming  which  came  from  three  suc- 
cessive large  heats,  and  was  never  known  to  occur  before 
in  the  cupola  used.  In  analyzing  the  slag  to  discover, 
if  we  could,  the  cause  of  the  slag  foaming,  we  also 
took  note  of  the  iron  it  contained.  The  slag  coming 
from  one  of  the  foaming  heats,  when  analyzed,  was 
found  to  contain  an  oxide  of  iron  equivalent  „ to  26.80 
per  cent,  metallic  iron.  In  addition  to  this  there  was 
1.97  per  cent,  of  very  fine  shot  iron  in  the  sample  of 
slag  selected,  which  was  an  average  of  the  whole  heat. 
This,  no  doubt,  was  from  droppings  of  melted  iron, 
which  elsewhere  than  at  the  slag  hole  would  have  greatly 
found  its  way  to  the  bottom  and  constituted  part  of  the 
liquid  metal  to  be  drawn  off  at  each  tap.  The  fine  shot 


320  METALLURGY    OF    CAST    IRON. 

iron  I  consider  is  likely  to  occur  in  any  heat,  the 
quantity  escaping  with  the  slag  being  dependent  on 
the  pressure  of  the  blast  and  the  size  of  the  slag 
hole. 

A  short  time  after  the  difficulty  with  foamy  slag 
I  gave  considerable  attention  to  iron  in  slags,  and  had 
analyses  made  by  Mr.  Mac  Shiras,  who  found  the  fol- 
lowing weights  of  iron  to  be  lost  through  slags:  In  a 
heat  of  forty  tons,  March  15,  1894,  we  had  slag  coming 
from  the  slag-hole  weighing  1,700  pounds.  The 
analysis  showed  this  slag  to  contain  3.34  per  cent,  of 
shot  iron  and  oxide  of  iron  equivalent  to  17.25  per 
cent,  metallic  iron,  a  loss  of  350  pounds  of  iron  in  the 
1,700  pounds  of  slag,  and  to  the  total  weight  of  iron 
charged  the  percentage  of  loss  would  be  thirty-nine 
one-hundredths  of  one  per  cent. 

Another  heat  of  forty  tons  on  March  19,  1894,  which 
we  followed  up,  showed  the  slag  weighed  1,630  pounds. 
The  analysis  of  this  gave  2.70  per  cent,  shot  iron  and 
an  equivalent  of  15.69  per  cent,  of  metallic  iron,  a  loss 
of  300  pounds  in  1,630  pounds  of  slag,  and  to  the  total 
weight  of  iron  charged  the  percentage  of  loss  would 
be  thirty-three  one-hundredths  of  one  per  cent.,  which, 
figuring  the  iron  at  $  1 2  per  ton,  would  show  a  loss  of 
$1.58,  or  a  little  less  than  four  cents  per  ton.  One 
factor  which  it  will  be  profitable  to  dwell  upon  before 
proceeding  further  is  the  reason  for  the  difference  of 
loss  in  the  two  forty-ton  heats.  As  our  metal  is  car- 
ried away  from  the  cupola  by  a  five-ton  ladle,  and 
there  are  often  lulls  in  getting  back  with  the  crane 
ladle,  I  permitted  the  practice  of  leaving  the  slag -hole 
open  all  the  time,  so  as  to  make  sure  that  the  slag  or 
metal  did  not  reach  the  tuyeres.  Feeling  satisfied  we 


LOSS    OF    IRON    BY    SLAGGING    OUT    CUPOLAS.  321 

were  losing  some  metal  by  letting  the  blast  continually 
blow  out  of  the  slag  hole,  I  decided  to  try,  in  the  second 
heat  quoted,  to  plug  and  tap  the  slag-hole  at  intervals, 
or  just  a  few  minutes  before  tapping  out.  By  doing 
so  we  obtained,  as  shown,  a  saving  of  six  one-hun- 
dredths  of  one  per  cent,  of  the  total  weight  of  iron 
charged,  or  in  other  words,  we  saved  29  cents  in  the 
heat  of  40  tons  at  the  risk  of  letting  the  iron  or  slag 
fill  up  the  tuyeres,  and  hence  bung  up  the  cupola.  By 
such  a  method  of  retarding  melting,  to  save  a  little  iron, 
we  might  have  lost  many  dollars  in  castings  through 
bad  melting  or  dull  iron. 

Where  conditions  are  favorable  to  tapping  a  slag- 
hole  at  intervals,  or  just  before  tapping  out  the  iron, 
on  account  of  having  a  greater  distance  between  the 
tuyeres  and  slag-hole,  then  we  had,  the  above  figures 
clearly  demonstrate  the  economy  of  such  practice ;  and 
it  is  one  that  as  a  general  thing  can  be  safely  followed ; 
but  in  cases  where  the  tapping  out  and  plugging  up  of 
a  slag-hole  would  require  a  man  solely  to  look  after  it, 
nothing  is  to  be  saved  by  this  practice.  We  used  all 
pig ;  no  scrap  excepting  a  few  ' '  gates, ' '  which,  for  a 
5o-ton  heat  would  weigh  about  two  tons;  and  Connells- 
ville  coke  for  fuel,  of  which  2,000  pounds  were  used  for 
the  bed  and  450  pounds  between  charges.  The  pig  on 
bed  was  8,000  pounds  and  between  charges  6,000 
pounds.  We  used  limestone  for  a  flux;  for  every 
three  tons  we  used  about  90  pounds,  placed  on  top  of 
every  charge.  There  is  no  doubt  that  one  or  two 
hundredweight  of  slag  could  be  added  to  the  totals 
given  above,  which  could  be  gathered  from  the  skim- 
ming of  the  ladle  and  the  dropping  of  the  bottoms. 
Our  apprehension  as  to  loss  of  iron  through  slag  was 


322  METALLURGY    OF    CAST    IRON. 

allayed  when  we  discovered  it  was  less  than  one -half 
of  one  per  cent. 

The  loss  of  pig  iron  through  oxidation  in  the  cupola, 
iron  in  the  slag  and  refuse  wheeled  out  from  under  the 
bottom,  etc,,  by  melting  in  a  cupola,  will  range  from 
three  to  six  per  cent,  of  the  total  weight  charged.  The 
more  sand  scale  on  pig  iron,  the  greater  the  loss. 
Unbroken  pig  iron  will  show  a  greater  loss  than  broken, 
for  the  reason  that  the  jar  of  breaking  it  over  an  iron 
block  loosens  the  sand  scale  so  that  when  the  iron  is 
thrown  into  a  car  for  shipment  from  the  furnace  yard 
the  purchaser  receives  less  sand  scale  on  his  pig  iron. 

Loss  of  scrap  iron  by  melting  in  a  cupola  is  given 
in  Table  66,  page  314,  and  discussed  on  pages  316  to 
318.  This  shows  that  the  loss  of  stove  plate  may  range 
from  ten  to  fifteen  per  cent,  or  more  and  heavier  scrap 
from  four  to  eight  per  cent,  or  more,  according  to  the 
scale  and  dirt  conditions  of  the  iron. 

We  can  look  to  oxidation  for  much  of  the  total  loss 
incurred  by  remelting  iron.  There  is  little  doubt  but 
that  most  of  the  loss  by  oxidation  is  done  above  the 
tuyeres,  as  the  metal  is  dropping  from  the  melting 
point  through  the  fuel  down  past  the  tuyeres  to  the 
bath  of  metal  in  the  bottom,  and  from  the  surface  of 
the  solid  metal,  at  or  above  the  melting  point,  as  it 
exposes  a  semi-molten  surface  to  the  effects  of  the  blast. 
The  more  surface  we  expose  to  the  effects  of  blast  the 
faster  the  oxidation,  hence,  with  light  scrap,  we  must 
expect  the  greater  loss.  There  are  reasons  why  one 
founder  should  lose  10  percent,  and  another  only  3  per 
cent. ,  in  remelting  cast  iron.  It  will  pay  any  founder 
to  closely  investigate  his  losses,  and  he  may  often  lessen 
them  by  intelligently  understanding  the  cause. 


CHAPTER  XLVII. 

COMPARATIVE  FUSIBILITY  OF  FOUNDRY 
METALS.* 

In  the  advance  of  founding  to  a  basis  of  greater 
exactness  and  assurance  of  successful  workings,  it  is 
often  as  essential  for  us  to  have  information  on  the 
fusibility  of  the  metals  we  make  mixtures  from,  as  to 
know  the  effect  of  one  metalloid  upon  another  in 
changing  the  physical  character  of  iron.  This  is  real- 
ized when  we  consider  how  easily  a  formulated  mixture 
can  be  prevented  from  giving  calculated  results,  by 
one  metal  having  a  lower  fusing  point  than  another 
when  charged  into  a  cupola.  While  this  is  a  subject 
of  importance  to  the  general  and  heavy-work  founder, 
who  is  often  called  upon  to  take  several  different 
grades  out  of  a  cupola  at  one  "  heat,"  it  is  also  of  im- 
portance to  the  specialty  and  light-work  founder  who 
may  be  charging  irons  of  different  grades  to  make 
one  or  two  mixtures  for  a  whole  heat,  for  when 
the  latter  knows  that  one  combination  of  certain  metal- 
loids requires  greater  heat  than  others  he  is  in  a  much 
better  position  to  decide  whether  it  is  the  iron,  blast, 
atmosphere,  fuel,  mischance,  or  his  own  mismanage- 

*This  chapter  comprises  two  papers,  revised  for  this  work, 
which  the  author  presented  respectively  to  the  Pittsburg  Foun- 
drymen's  Association  in  June,  1897,  and  to  the  Western  Foundry- 
men's  Association  at  Cincinnati,  in  October  of  the  same  year. 


324  METALLURGY    OF    CAST    IRUix. 

ment  that  makes  the  cupola  irregular  in  its  meltings 
so  that  it  produces  hot  iron  one  day  and  dullish  iron 
the  next,  also  harder  iron  than  desired  with  resulting 
bad  work  or  heavy  losses  in  castings.  Knowing  how 
very  important  it  is  to  possess  definite  knowledge 
concerning  what  causes  grades  of  iron  to  differ  in  their 
fusibility,  I  decided  to  experiment  and  learn,  if  pos- 
sible, the  effect  of  different  combinations  of  the  metal- 
loids on  the  fusing  point  of  iron.  In  searching  for 
appliances  that  would  give  reliable  data  I  failed  to 
find  anything  satisfactory,  and  therefore  set  to  work 
to  devise  something  that  would  meet  the  requirements 
and  at  the  same  time  withstand  criticism.  One  objec- 
tion I  have  to  past  methods  of  testing  the  fusibility 
of  metals,  is  the  failure  to  provide  conditions  similar  to 
those  used  in  actual  founding.  To  meet  the  con- 
ditions of  actual  practice,  I  studied  out  a  design  of 
cupola  (see  Fig.  56,  page  241)  which  is  an  original 
arrangement,  so  far  as  I  know.  The  method 
adopted  gives  only  comparative  results  and  does 
not  show  the  degree  of  heat  required  to  fuse  any 
of  the  metals.  Observations  may  be  made  and  con- 
clusions drawn  from  them  as  to  the  difference  in  the 
time  of  melting  which  any  grade  of  metal  requires 
over  another,  when  the  two  kinds  of  iron  are  charged 
in  the  respective  sides  shown.  It  will  appear  upon 
examination  that  like  conditions  must  prevail  in  both 
apartments,  and  that  if  one  grade  starts  or  comes  down 
quicker  than  another  we  know  it  to  have  a  lower  fusing 
point.  By  a  series  of  such  tests  we  are  in  position  to 
formulate  a  scale  showing  the  combinations  of  metal- 
loids requiring  the  highest  heat,  with  the  relative 
gradations  of  others,  down  to  that  most  readily  fused. 


COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.      325 

The  comparative  test  cupola  seen  on  page  241  is  not 
an  expensive  affair,  and  is  such  as  might  often  be  a 
valuable  adjunct  to  the  laboratory  of  metallurgists, 
blast  furnaces,  foundries,  etc.,  besides  being,  useful 
for  the  production  of  repairs  for  breakdowns,  etc., 
and  then  again  for  small  castings,  which  it  may  be 
desirable  to  make  of  two  separate  grades  of  metal.  It 
will  be  well  to  state  that,  where  only  one  kind  of  iron 
is  desired  to  be  melted  the  center  blast  can  be  closed 
and  the  iron  made  to  run  to  one  tap  hole  by  having 
one  slanting  bed  as  in  regular  cupola  practice. 

In  designing  the  cupola  (Fig.  56)  I  arranged  fora 
center  blast,  besides  having  outside  tuyeres  on  the  plan 
shown.  This  permits  the  greatest  possible  uniformity 
of  combustion  throughout  the  area  of  the  cupola  and 
affords  every  opportunity  of  regulation  should  the  heat, 
from  any  cause,  be  greater  in  one  portion  than  in 
another.  This  regulation  is  secured  by  diminishing  or 
increasing  the  volume  of  blast  by  valves  attached  to 
branch  pipes,  not  shown,  leading  to  the  tuyere  open- 
ings A  A,  B  B,  and  E.  It  may  be  asked,  How  is  it 
possible  to  know  when  there  is  perfect  uniformity  of 
heat  all  over  the  area  of  the  cupola?  This  is  indicated 
by  the  color  of  the  flame  emanating  from  the  open  top 
of  the  cupola.  If  any  difference  should  exist  there  on 
either  side,  the  eye  will  detect  it  as  quickly  as  the  steel 
maker  can  note  changes  taking  place  in  a  Bessemer 
converter  by  means  of  the  spectroscope. 

In  operating  this  cupola  the  sand  bed  is  put  in  with 
two  slanting  bottoms,  as  seen  at  H  H,  thus  preventing 
either  metal,  as  it  comes  down,  from  mingling  with 
the  other.  The  center  tuyere  has  three  pieces  of 
round  iron  laid  over  its  opening,  as  seen  at  M, 


326  METALLURGY    OF    CAST    IRON. 

to  prevent  the  fuel  from  dropping  into  it  and  stopping 
its  blast  passage.  Good  kindling  is  used  up  to  within, 
say,  1 2  inches  of  the  top.  On  this,  coke  broken  to  about 
double  egg  size,  is  then  placed.  The  coke  is  poked 
down  as  the  fire  burns  until  there  is. a  solid  bed  of  live 
coals  up  to  within  15  inches  of  the  top.  If  the  metal 
to  be  fused  is  of  a  light  character,  or  easily  melted,  it 
is  then  charged  at  this  height ;  but  if  it  is  heavy  or 
hard  to  liquefy,  then  the  bed  of  live  fuel  should  extend 
up  to  about  12  inches  from  the  top,  as  shown  by  the 
pigs  at  X.  As  this  cupola  has  ample  tuyere  area  evenly 
divided,  it  can  be  worked  with  a  mild  or  strong  blast, 
as  may  be  desired.  The  tap  holes  at  D  D  are  left  open 
so  as  to  permit  the  metal  to  flow  out  as  fast  as  it  melts, 
thus  allowing  a  record  to  be  made  of  the  metal's  first 
and  last  appearance.  Of  course,  should  the  cupola  be 
used  simply  for  the  purpose  of  melting  to  get  metal  to 
pour  a  casting,  it  could  then  be  stopped  and  tapped 
the  same  as  any  cupola  used  in  ordinary  practice.  If 
the  cupola  is  employed  for  testing  the  comparative 
fusibility  of  metals,  it  may  often  require  about  six 
men  to  operate  it  —  one  for  timekeeper,  one  to  charge 
on  fuel  evenly  and  press  it  down  so  as  to  preserve  a 
solid  fire  until  the  iron  is  about  half  down,  one  at  each 
tap  hole  to  keep  it  open  that  the  rnetal  may  flow  freely, 
and  then,  if  the  metal  is  to  be  caught  into  moulds,  two 
men  on  each  side  to  take  away  the  filled  moulds  and 
replace  empty  ones.  If  the  cupola  is  only  to  be  used 
to  obtain  metal  to  pour  a  small  casting,  or  to  record 
the  time  of  fusing  by  letting  the  metal  down  into  a 
ladle  or  * '  pig  "as  it  comes  out,  then  two  men  are 
sufficient  to  operate  it.  In  charging  any  metal  for  a 
comparative  test,  care  must  be  exercised  to  have  the 


COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.      327 

bed  of  the  fuel  the  same  height  on  both  sides,  also  to 
have  each  grade  of  metal  as  nearly  uniform  in  size  as 
possible,  and  evenly  charged.  After  this,  coke  is  filled 
in  until  the  cupola  is  stocked  to  its  brim,  when  it  is 
ready  for  the  blast. 

The  first  test  heat  made,  as  seen  by  the  Table  70, 
consisted  of  150  pounds  on  each  side,  it  being  put  in 
with  50  pounds  in  two  charges  after  the  bed  of  50 
pounds  was  on.  This  plan  was  found  to  be  objection- 
able for  comparative  testing,  as  it  showed  wherein 
errors  might  easily  be  made  by  reason  of  uneven 
charging,  the  escaping  flame  making  it  too  hot  for  the 
charger  to  always  place  the  iron  in  evenly.  After  this 
first  heat  no  more  metal  was  charged  than  the  bed 
could  carry  well,  thus  permitting  all  iron  to  be  care- 
fully charged  before  the  blast  went  on.  The  plan 
adopted  for  comparative  tests  of  Table  70  was  to  make 
at  least  two  casts  of  each  grade,  the  first  being  that  of 
the  metal  in  its  original  state,  each  grade  being  broken 
to  uniform  size,  as  far  as  possible.  This,  in  being 
melted  down,  was  run  into  moulds  that  gave  blocks 
weighing  about  1 5  pounds  each  and  in  size  2^x4x6 
inches.  For  the  second  cast  of  each  grade  these 
blocks,  in  the  larger  heats,  were  broken  in  two  pieces, 
but  where  there  were  only  two  blocks  for  each  side 
they  were  charged  whole.  The  idea  of  running  the 
first  heat  of  pig  metal  or  scrap  into  blocks,  as  stated, 
was  to  obtain  metal  that  would  be  closely  uniform  in 
size  and  weight  and  better  insure  like  conditions  in 
making  a  comparative  test,  an  important  requisite. 
This  appears  in  Table  70,  in  the  columns  marked 
alternately  "  pig  "  and  "  block."  Up  to  the  time  of 
writing  this  paper  I  have  made  nineteen  comparative 


328 


METALLURGY    OF    CAST    IRON. 


tests,  but  only  give  results  of  eight  of  them  here,  for 
the  reason  that  in  the  case  of  the  others  I  desire  to  make 
experiments  that  will  require  much  time,  and  that 
should  be  compiled  with  the  second  series  to  give 
complete  results  in  that  line  of  inquiry.  As  the  first 
series  of  tests  is  distinct,  in  showing  what  effect  low 
silicon  and  high  sulphur  have  upon  the  fusibility  of 
iron,  as  compared  with  high  silicon  and  low  sulphur 
with  the  total  carbon  and  the  ' '  iron  ' '  closely  constant, 
I  permitted  the  appearance  of  this  paper  at  the  re- 
quest of  the  secretary.  The  second  series  of  tests 
is  given  in  pages  332  to  344. 

TABLE  NO.    70 — COMPARATIVE  FUSING  TESTS   OF  HIGH  AND  LOW  SILICON 
AND  LOW  SULPHUR  IRONS. 


44  Heat  "  Nos. 

i 

2 

3 

4 

5 

6 

7 

8 

Form  of  iron  charged 

Pig. 

Block. 

Pig. 

Block. 

Pig. 

Block. 

Pig. 

Block. 

Weight   of    iron 
charged  each  side.. 

150 

65 

IOO 

54 

40 

35 

64 

50 

Blast  turned  on  

i:55 

i:35 

2:13 

2:08^ 

4:21 

1:56 

1:44 

2:26 

Harder  iron  running 

i:57 

i:39 

2:21 

2:1254 

4:27 

2:02^ 

i  :,so 

2:32% 

Softer  iron  running.. 

i:57% 

1:40 

2:215^ 

2:13^ 

4:28 

2:02 

i:5o5* 

2:34^ 

First  mold  of  harder 
iron  filled  

i:59 

1:42 

2:24 

2:16 

4:31% 

2:0654 

2:55 

2:37K 

First  mold  of  softer 
iron  filled  

2:01 

i:43 

2:24 

•2:155* 

4o2% 

2:07 

2:55% 

2:38% 

Second    mold   of 
harder  iron  filled... 

143 

2:26 

2:17 

4:36 

2:57 

2:40 

Second  mold  of  softer 
iron  filled  

1:44 

2:26 

2:16% 

4:38% 

2:58 

2:41 

Third     mold     of 
harder  iron  filled... 

1:44 

2:2714 

2:17^ 

Third  mold  of  softer 
iron  filled  

i:45 

2:28 

2:17% 

Harder  iron  all  down 

2:i954 

1:49 

2:37^ 

2:18 

4:37 

2:0954 

2:02% 

2=475* 

Softer  iron  all  down. 

2:22 

1:50 

2:39 

2:1854 

4:40 

2:11 

2:05 

2:4854 

Time  of  melting  

j.Siu. 

inn. 

[(,'..111. 

6m. 

13111. 

lorn. 

15111. 

i5%m. 

First  iron  to  melt  

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Time    exceeding  its 
mate  

45  s. 

i  m. 

10  s. 

45  s. 

i  m. 

15  S. 

Mil    30S 

im  45S 

First  iron  all  down... 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Hard. 

Time  exceeding    its 
mate. 

2in  303 

i  m. 

im  308 

3os. 

3tn. 

im  308 

2111  158 

i  m. 

COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.      329 
TABLE    71.— CHEMICAL   ANALYSIS   OF    TABLE    70. 


Analysis  Letter. 

A 

B 

c 

D 

Total  Carbon  

4-25 

4-03 

4-15 

4.10 

Graphite  Carbon  

2.07 

1.76 

1.94 

3-92 

Combined  Carbon  

2.18 

2.27 

2.21 

.18 

.Silicon           

•85 

.92 

•99 

2.70 

Sulphur.  

.21 

•19 

•  17 

•03 

Manganese  

.18 

•  i? 

.26 

•34 

Phosphorus  

.192 

.129 

.655 

.085 

Iron  by  difference 

94.32 

94.56 

93-77 

y2-74 

The  importance  of  this  work  will  be  better  under- 
stood when  it  is  stated  that  at  the  present  time  (1897) 
some  are  laying  claim  to  tests  proving  that  soft,  grades 
of  all  irons  will  melt  down  faster  than  hard  irons.  The 
contrary  results  have  chiefly  been  my  experience,  and 
appear  to  be  the  general  expression  on  this  question. 
Still,  I  hold,  as  stated  in  the  early  part  of  this  paper, 
that  results  are  often  affected  by  combination  of  the 
metalloids  as  well  as  by  the  physical  character  of  the 
iron,  and  I  believe  my  second  paper  will  bear  me  out 
in  this  assertion.  I  desire  here  to  thank  Dr.  Richard 
Moldenke  and  the  McConway  &  Torley  Co.  of  Pitts- 
burg  for  the  assistance  rendered  me  in  this  work  by 
furnishing  metals  and  complete  analyses  of  the  irons 
shown. 

Referring  to  the  preceding  tables,  attention  is  first 
called  to  the  analyses.  The  column  under  A,  Table 
71,  is  that  of  hard  iron  in  heats  Nos.  i  and  2.  B  is 
that  of  a  white  iron  used  for  heats  .  Nos.  3  and  4,  C  is 
that  of  a  mottled  iron  used  for  heats  Nos.  5,  6,  7,  and 
8,  while  D  is  the  analysis  of  a  soft  iron  used  as  a  com- 
parative constant  to  the  hard  irons  throughout  the 
eight  heats.  It  may  be  stated  that  •  drillings  for 


330  METALLURGY    OF    CAST    IRON. 

analyses  were  all  taken  from  the  blocks  as  they  came 
from  the  first  casts  of  the  original  pig  or  scrap  metal. 

In  all  the  heats  the  hard  iron  is  seen  to  have  come 
down  first,  excepting  in  one  case  which  is  foimd  in 
heat  No.  6,  and  that  the  flow  of  hard  iron  ended 
soonest  in  all  the  heats.  Thus,  as  far  as  these  tests 
go  they  show  that  hard  iron  will  melt  faster  than  soft, 
and  confirm  my  past  assertions  and  the  general  impres- 
sion existing  among  old  experienced  founders  that 
hard  iron  will  melt  more  readily  than  soft  grades. 

An  interesting  discussion  followed  the  reading  of 
the  paper.  Dr.  Richard  Moldenke  contributed  the 
following :  * '  Long  experience  with  the  melting  of  iron 
in  Siemens-Martin  furnaces  having  given  me  the 
impression  that  hard  irons  melt  faster  than  soft  ones, 
and  knowing  this  to  be  the  accepted  view  among  the 
trade,  I  was  not  a  little  astonished  to  see  claims 
advanced  insisting  on  the  contrary.  At  the  time  I 
thought  it  likely  to  be  owing  to  some  radical  difference 
in  the  composition  of  the  irons  that  were  used,  and  was 
therefore  more  than  pleased  to  hear  Mr.  West  advance 
the  idea  of  making  comparative  tests  to  settle  the 
matter  definitely.  It  has  remained  for  him  to  devise 
a  most  excellent  system  of  melting  to  accomplish  this 
result,  and  I,  for  one,  have  been  much  interested  in 
the  working  of  his  "  twin  shaft  cupola  "  (Fig.  56),  if  I 
may  so  call  it.  It  will  give  us  ready  means  of  com- 
paring the  fusibility  of  the  required  brands  of  iron 
going  into  our  cupola  charges.  The  few  words  I  have 
to  add  relate  to  the  melting  of  iron  in  the  open -hearth 
furnace,  where  there  is  obviously  no  difficulty  due  to 
the  rate  of  melting,  since  everything  charged  is  sup- 
posed to  make  up  a  bath  of  uniform  composition.  I 


COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.      33! 

made  two  experiments,  charging  simultaneously  in 
each  case  two  pigs  of  equal  weight  and  shape,  one 
being  soft,  the  other  hard.  It  will  be  observed  that  in 
the  open -hearth  furnace,  filled  up  with  a  charge  just 
melting  down,  these  two  pigs  thrown  on  top  of  the 
white  hot  metal,  and  in  the  full  head  of  the  furnace, 
could  be  closely  watched  with  the  aid  of  blue  glass 
spectacles.  In  the  first  experiment  I  was  surprised  to 
find  the  soft  pig  melting  first.  It  became  soft  and 
could  be  broken  up  by  the  bar,  behaving  much  like  a 
plumber's  wiping  metal  when  it  is  just  soft  enough  to 
work.  This  soft  pig,  when  thus  crushed,  looks  like 
silver,  and  makes  one  wish  for  time  and  opportunity 
to  study  the  characteristics  of  the  carbons  while  in  this 
state.  The  hard  pig,  on  the  contrary,  retained  its 
form  remarkably  well,  not  disintegrating  like  the  soft 
one  did,  the  melted  portions  dropping  off  like  water. 
Further  investigation  developed  the  fact  that  the  soft 
iron  which  melted  first  was  about  55  points  higher  in 
the  total  carbon  than  the  hard  iron.  (The  author  held 
that  difference  in  the  graphitic  and  combined  carbons 
would  affect  results  as  seen  on  pages  154  and  329.) 
Mr.  West,  in  his  second  paper,  will  go  into  this  question 
fully,  as  he  is  making  extended  experiments  in  this 
line.  The  other  trial  was  with  two  irons  of  the  same 
brand,  shape,  and  weight.  They  had  very  nearly  the 
same  manganese,  sulphur,  phosphorus,  and  total  car- 
bon, but  one  had  twice  as  much  silicon  as  the  other, 
resulting  in  3.37  percent,  graphite  in  the  soft  pig,  and 
only  .  68  per  cent,  in  the  hard  white  one.  In  melting 
these  two  pigs  under  exactly  the  same  conditions, 
the  hard  one  went  first.  It  held  its  form  well,  but 
in  melting  ran  like  water,  and  was  melted  before 


332  METALLURGY    OF    CAST    IRON. 

the  soft  iron  was  half  gone.  The  soft  iron  melted 
sluggishly,  and  did  not  hold  its  form  while  melting  as 
well  as  the  hard  iron.  It  was  very  interesting,  even  if 
trying  to  the  eyes,  to  observe  the  whole  process,  and 
now  that  Mr.  West  has  gone  into  the  whole  matter 
so  thoroughly,  we  will  certainly  be  able  to  crystallize 
our  ideas  and  know  what  we  may  look  for  in  making 
up  important  charges. ' ' 


REVISION    OF   SECOND    PAPER  ON   FUSI 
BILITY  OF  FOUNDRY  METALS. 

This  second  paper,  aside  from  presenting  several 
important  discoveries  made  by  the  author,  shows  that 
a  chilled  body  of  iron  will  melt  faster  and  require  less 
heat  than  a  gray  body,  both  having  been  poured  from 
the  same  ladles  or  cast  of  iron,  and  that  steel  proper 
requires  higher  heat  than  cast  iron  to  fuse  it ;  also  that 
remelting  of  steel  in  contact  with  incandescent  fuel 
wholly  destroys  its  original  character.  Making  com- 
parisons of  the  fusibility  of  gray  and  chilled  bodies, 
both  of  the  same  composition  excepting  the  combined 
carbon,  was  accomplished  by  the  following  plan.  A 
heat  of  chilling  or  low  charcoal  iron,  designated  as 
heat  No.  9,  Tables  72  and  73,  was  caught  in  hand  ladles 
and  then  poured  into  sand  and  chill  moulds,  placed 
side  by  side.  A  view  of  the  chill  mould  and  chill  roll 
cast  in  it  is  seen  at  Figs.  58  and  59,  page  312.  This 
gives  a  wholly  gray  body  of  iron  in  the  casting  coming 
from  the  sand  mould,  and  a  wholly  chilled  or  white 
crystallized  body  of  iron  from  the  chill  or  all-iron 
mould ;  both,  it  is  to  be  remembered,  being  poured 


COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.     333 

from   the   same  ladle   of  iron.     The  fractures  of  the 
gray   and   chilled   iron   are    shown   in   Figs.    61    and 
62,  this  page  and  337. 
The  gray  and  sand  rolls  which  were  used  in  these 


FIG.   6l. — GRAY    ROLL. 
Combined  Carbon,  1.20.  Graphitic  Carbon,  2.90. 

comparative  tests  were  all  tumbled,  so  as  to  get  the 
sand  off  them  thoroughly  before  they  were  charged. 
Before  explaining  the  results  and  tests  shown  by  Tables 
72  and  73,  next  page,  we  will  describe  the  plan  fol- 
lowed in  conducting  the  heats  shown : 

For  heat  No.  9, Table  72,  charcoal  pig  iron  was  charged 
in  both  chambers  of  the  cupola  and  run  out  of  one  tap 


334 


METALLURGY    OF    CAST    IRON. 


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COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS. 

TABLE    73. — CHEMICAL   ANALYSIS   AND   SPECIFIC  GRAVITY   OF   GRAY 
AND   CHILLED   IRONS   RAN   FROM   HEATS   SHOWN   IN   TABLE    72. 


Heat  Nos. 

9 

IO 

II 

12 

Analysis  of  Castings 
obtained  from  the 
i2th  heat. 

Kind  of 
metal 
charged. 

Analysis 
letter  

i-5?  • 

ill 

•§! 

&z 

r-,W 

2*3 
UK 

111 

5*M 

111 

Otfffi 

^  «j 

is. 

F 

~£ 

!H"o 

<J& 

*£ 

11 

^ri 

si 

rO^fi 

So 

$* 

^3,2 

!S"o 

UK 

A 

B 

c 

*D 

fc^ 

G 

H 

i 

J 

K 

Total 
Carbon.. 

3-94 

4.10 

4.06 

4-30 

4-3° 

4-47 

4.40 

4.68 

4.62 

4.76 

4-7" 
0.03 
4.67 

Graphitic 
Carbon... 

3-o6 

2.90 

0.16 

2.42 

2.68 

2.90 

O.2O 

2.67 

o.oo 

3.16 

Combined 
Carbon  . 

.88 

1.  20 

3-90 

1.98 

1.62 

1-5; 

4.20 

2.OI 

4.62 

1.60 

Silicon  

.82 

•75 

•75 

•63 

.68 

.66 
•04 

.63 

•57 

.56 

•59 

•57 
.044 

Sulphur.... 

.02 

•03 

•03 

.04 

•035 
•54 

.04 

•045 

.046 

.048 

Manganese 

.78 

.66 

.66 

•53 

•3i 

•33 

.18 

.19 

•25 

.22 
.266 

7-79 

Phos- 
phorus... 

.232 

.248 

.240 

.274 

•285 

•237 

•254 

•254 

.250 

.271 

Specific 
Gravity... 

7.01 

7-30 

7.61 

7-35 

7.40 

7.70 

7-47 

7.76 

7.46 

hole,  the  metal  being-  poured  into  sand  and  chill  moulds 
from  one  ladle.  For  heat  No.  10  the  sand  and  chill 
rolls  from  heat  No.  9  were  charged  in  their  respective 
sides  and  the  two  tap  holes  used.  The  iron  as  it  ran 
from  this  heat  through  open  tap  holes  dropped  into 
sand  moulds,  one  being  set  under  each  tap  hole,  to 
give  a  block  of  iron  from  each  side  about  six  inches 
diameter  by  six  inches  high.  This  tenth  heat  had  both 
sides  run  into  sand  moulds  for  the  purpose  of  learning 
which  would  be  the  harder  iron  when  remelted,  that 
which  had  been  chilled  or  that  which  had  riot.  Heat 
No.  ii  melted  down  the  gray  blocks  obtained  from 
heat  No.  10,  and  this  iron  was  again  run  into  sand  and 
chill  moulds.  Heat  No.  12  was  a  remelt  of  the  sand 
and  chill  rolls  obtained  from  heat  No.  n,  and  was  the 

*  The  analyses  D  and  E)  of  the  grey  blocks  coming  from  the  sand  and  chilled 
rolls  cast  in  heat  No.  10  and  melted  down  in  heat  No.  n  is  also  shown  at  A2 
and  B2,  Table  74,  page  336. 


336 


METALLURGY    OF    CAST    IRON. 


fourth  and  last  heat  of  a  continuous  remelt  of  the  orig- 
inal charcoal  pig  used  in  heat  No.  9.  The  metal  from 
heat  No.  1 2  had  each  side  poured  into  sand  and  chill 
moulds,  and  the  analyses  at  H,  I,  J,  and  K,  Table  73, 
show  the  chemical  changes  made  by  the  twelfth  heat. 
Heats  13  and  15  were  casts  in  which  the  same  grade  of 

TABLE  74. — CHEMICAL  ANALYSIS  OF  CHILLED  AND  GRAY  IRON  RE-MELTS, 
POURED  INTO  SAND  MOLDS  BY  HEATS  SHOWN  IN  TABLE  J2,  PAGE  334. 


•sjJTJS 

•S«-d5 

°^^5 

o-g^g 

°^| 

Description  of 

2-  a  ° 

tfiO  «~ 

»o  a" 

w  rt  °T3  rt 

.15* 

iron  and 

^  ^     M 

tfl  fo  *"* 

t/;  *O 

U5  'p         h/iJ3 

"§^•3 

heat  No. 

~>>-^  g±j 

^  ^-2  s  ^* 

*W#d 

^«t3  £r 

*>»2g~ 

Ifell 

|loll 

SS^gS 

g  X  rt  -C  "o 
^  u  tc  o  (s 

«24>oS 

3bOo£.C 

Classification 
of 
re-melts. 

Sand  roll 
re-melt. 

I 

•si 

|| 

Chill  roll 
re-melt. 

i! 

id 

_  4J 

•73  3 

a  JJ 

Sand 
rolls  as 
charged. 

Chill 
rolls  as 
charged. 

Sand  roll 
re-melt. 

Chill  roll 
re-melt. 

Analysis  Letter. 

A2 

B2 

C2 

D2 

E2 

Fa 

G2 

H2 

12 

J2 

Total  Carbon... 

4.30 

4.30 

4-30 

4-30 

2.94 

3-i5 

3-55 

3-6o 

3.88 

3-95 

Graphitic  C'rb'n 

2.42 

2.68 

2.20 

3-20 

2.41 

2-73 

2.63 

2.05 

2.15 

2.40 

Combined 

Carbon  

1.98 

1.62 

2.10 

I.IO 

•53 

.42 

.92 

1-55 

i-73 

1-55 

Silicon  

•63 

.68 

•75 

.87 

•55 

.69 

1-55 

1-57 

1.29 

1-39 

Sulphur  

.04 

•035 

.04 

.035 

•045 

.048!     .030 

.030 

.042 

.040 

Manganese.. 

•53 

•54  |     -48 

.62 

1.23 

1.32 

•i33l     -135 

.126 

•  130 

Phosphorus.  ... 

.274 

.285!     .283 

.241 

1.07 

1.07 

•343  '     -330 

•364 

•350 

pig  was  used  as  in  heat  No.  9  as  a  check  to  learn  if 
similar  results  would  be  obtained  by  further  experi- 
ments, and  heats  14  and  16  are  used  as  a  check  on  heat 
No.  10,  in  the  same  manner. 

The  analyses  given  under  A,  B,  and  C,  Table  73,  for 
heats  Nos.  9  and  10  will  also  serve  for  heats  13  to  16. 
When  running  the  sixteenth  heat  the  sand  and  chill 
roll  metal  was  run  into  sand  moulds,  as  described  for 
heat  No.  10.  Heat  No.  17  is  a  high  manganese  and 
phosphorus  pig,  which  was  run  into  sand  and  chill 
moulds  to  make  rolls  that  were  used  for  heat  No.  18, 


COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.      337 

from  which  the  gray  and  chilled  metals,  as  they  came 
down,  were  both  run  into  sand  moulds.  Heat  No.  19 
is  a  No.  2  Foundry  all-coke  iron  which  was  also  run 
into  sand  and  chill  moulds.  Heat  No.  20  is  made  from 


Combined  Carbon,  3.90. 
FIG. 


62. 


Graphite  Carbon,  0.16. 
nilLLED    ROLL. 


the  sand  and  chill  rolls  obtained  from  the  nineteenth 
heat,  both  of  which  metals  were  run  into  sand  moulds 
as  heats  Nos.  10,  16,  and  18.  Analyses  of  the  gray 
and  chill  roll  remelts,  that  were  poured  into  sand 
moulds  to  test  whether  chilled  or  grey  parts  of  the  same, 
casting  would  give  the  softer  iron,  are  all  shown  in 


338  METALLURGY    OF    CAST    IRON. 

Table  74.      The  analyses  A  2  and  I>2  are  also  shown  in 
Table  73,  at  D  and  E,  page  335. 

It  was  the  belief,  until  the  author's  discoveries 
proved  the  contrary,  that  an  iron  once  chilled  would, 
upon  being  remelted,  produce  a  much  harder  casting 
than  if  the  same  iron  had  never  been  chilled.  This 
belief  was  so  strongly  maintained  by  founders,  prior 
to  the  author's  discovery,  that  in  selecting  scrap  iron 


GRAY  ROLL.     FIG.  63.     CHILLED  ROLL. 

for  mixtures  with  pig  metal  to  make  light  or  heavy 
machinery  castings,  etc.,  founders  would  reject  the 
scrap  that  had  been  chilled,  if  it  could  be  done,  lest  it 
might  cause  hard  spots  in  a  casting  or  make  the  whole 
too  hard.  Of  course,  it  is  to  be  understood  that  if  a 
casting  shows  a  chill,  it  is  evidence  that  the  gray  body 
of  the  casting,  if  used  for  scrap,  is  not  accepted  as  a 
soft  iron,  as  if  no  part  of  the  casting  exhibited  a  chill ; 
for,  as  a  rule,  founders  know  such  fractures  are  not  to 
be  graded  as  soft  iron.  Nevertheless,  they  did  not 


COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.     339 

know  that  a  chilled  iron  body  would  give  a  casting 
slightly  softer  than  if  the  chilled  part  had  been  rejected 
and  only  the  gray  body  utilized.  While  this  knowl- 
edge would  always  have  been  of  much  value  to  the 
founder,  there  has  been  no  time  that  it  could  be  turned 
to  more  profitable  account  than  at  the  present.  It 
may  be  asked  what  evidence  there  is  aside  from  the 
drilling  tests  to  prove  that  the  chill  roll  remelt  was 
softer  than  that  of  the  gray.  This  is  answered  by 
referring  to  the  columns  62,  D2,  F2,  and  J2,  Table  74, 
and  noting  the  greater  silicon  and  graphitic  carbon 
existing  in  the  chill  remelt  than  is  found  in  the  gray, 
as  seen  at  A2,  €2,  E2,  and  12.  The  author's  attention 
was  first  drawn  to  the  fact  that  the  chill  remelt  was 
softer  than  that  of  the  gray,  by  drilling  to  obtain 
material  to  make  the  analyses.  The  drill  worked  so 
much  easier  in  the  chill  remelt  than  in  the  gray  as  to 
be  a  matter  of  much  surprise.  The  drill  press  used  is 
shown  at  Fig.  53,  page  239.  After  a  well  sharpened 
twist  drill  was  attached  and  all  ready,  the  drill  was 
started  and  allowed  to  run  exactly  half  a  minute.  By 
drilling  several  holes  in  the  manner  described  on  page 
234,  alternately  in  each  of  the  respective  blocks,  we 
could  then,  by  measuring  their  depth,  intelligently  tell 
which  of  the  two  was  the  softer.  It  is  to  be  said  that 
the  drillings  of  the. whole  four  heats,  Nos.  10,  16,  18, 
and  20,  showed  the  chill  remelt  to  be  softer  than  those 
of  the  gray  iron.  It  will"  be  noticed  also  that  these 
four  remelts  are  distinct  in  testing  different  grades  of 
iron,  so  as  to  cover  a  wide  range  of  metals,  from  those 
that  would  take  but  a  slight  chill  on  the  surface  of  pig 
metal  or  a  casting  up  to  those  that  would  chill  its  whole 
body  as  displayed  in  Fig-.  62. 

Attention  is  again  called  to  the  specific  gravity  tests 


340 


METALLURGY    OF    CAST    IRON. 


seen  in  Table  73,  page  335,  which,  in  four  successive 
remelts,  raised  the  density  of  the  gray  iron  from  7.01 
to  7.46,  an  increase  of  .45  in  density,  and  in  the  chilled 
iron  to  7.79,  an  increase  of  .78  from  the  original  pig, 
showing  that  successive  remelts  greatly  increase  the 
density  of  irons.  Another  point  to  be  noticed  is  that 
the  chilled  iron  differs  about  .30  in  density  from  the 
gray  iron  in  the  respective  heats  shown.  For  a  com- 
parison of  the  specific  gravity  of  other  metals  with  cast 
iron,  see  Table  136,  page  593. 

TABLE    75- — COMPARATIVE   FUSION   TEST   OF    CAST   IRON   WITH    OPEN 
HEARTH    STEEL. 


Heat  Nos. 

21 

22 

23 

24 

25 

26 

27 

28 

Kind,  Weight 
and  Form  of 
Metal  Charged 
Each  Side. 

J 

c  c  S 

afi 

dS 

cfl 

o'~o 

2~£ 

2-  ° 

o     o 

0        0 

o    -o 

0       0 

8l 

JF 

ots-d 
4iJ 

x« 

^  rt 
vo 

J« 

°i« 

°  1c  o 

"S  c3 

IF 

Blast  put  on  ... 

8:56 

2:50 

3:00 

11:30 

3:23 

10:37 

11:29 

3:26 

Steel  running.. 

9:09^ 

2:59^ 

3:05 

"41  tf 

3:32 

10:45% 

11:385* 

3:3- 

Iron  running... 

9:06% 

2:58 

3:04 

11:38 

3:30^ 

10:45 

11:36% 

3:32^ 

Steel  all  down. 

9:21 

3:08 

3:11^ 

11:51 

3:41^ 

10:58^ 

11:49% 

Iron  all  down.. 

9:17^2 

3:05^ 

3:10 

11:48 

3:40 

10:58 

n-49 

Iron    exceeded 
steel  in  start- 

3m. 

im.  303. 

im. 

3m.  158. 

im.  305. 

45S. 

im.  308. 

158. 

Iron    exceeded 
steel    in    fin- 
ishing..   

3m.  308. 

2m.  308. 

im.  153. 

3m. 

im.  153. 

308. 

45S. 

Chemical  changes  due  to  remelting  iron.  In  a  study 
of  Table  No.  73  we  are  first  struck  by  the  increase  of 
total  carbon.  We  find  that  starting  with  the  original 
pig  containing  3.94  carbon,  four  re-melts  increased  it 
to  4.76,  an  increase  of  nearly  one  per  cent.  It  is  to  be 
noted  that  in  all  cases  the  sand  or  gray  rolls  show  more 
carbon  than  the  chilled  roll. 


COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.      34! 


TABLE    76. — CHEMICAL   ANALYSIS   OF   GRAY    CAST   IRON    AND   OPEN 
HEARTH    STEEL   RE-MELTS    GIVEN    IN    TABLE    75,  OIPOSITE   PAGE. 


Analysis 

Analysis  of 

of  metal 

metals 

Heat  Nos. 

21 

22 

23 

obtained 

charged  in 

from  the 

heats  Nos. 

23d  heat. 

24  to  26. 

a 

1 

c 

"3 
i 

c 

'v 
<u 

1 

a 

| 

d 

1 

Z 

X 

P 

A 

p 

,c 

o 

J3 

o 

A 

Kind  of  Metal 

§ 

"£ 

f 

£ 

"* 

t; 

Charged. 

8 

D 

,e 

X 

8 

0 
X 

1 

1 

"S 

8 

1 

i 

1 

>, 

p 

>> 

a 

>> 

c 

£**! 

g 

>» 

d 

| 

CO 

I 

CO 

8, 

Oj 
IH 

& 

z 

| 

0 

O 

O 

O 

O 

o 

O 

o 

0 

O 

Analysis  letter 

L 

M 

N 

O 

P 

Q 

R 

s 

T 

u 

Total  carbon... 

4.02 

.60 

1.48 

2.74 

4.60 

3-05 

4.20 

.70 

Graphitic 

carbon  

2.90 

3-30 

.15 

3-03 

trace 

Combined 

carbon  

1.  12 

.60 

1.48 

2.74 

1.30 

2.90 

1.17 

.70- 

Silicon.... 

1.72 

•31 

.26 

.14 

I-I5 

•35 

1.24 

.38 

Sulphur  

•03 

.026 

.10 

.14 

.10 

.18 

•05 

.12 

Manganese 

-35 

•34 

•23 

•  15 

•  23 

.06 

.40 

•59 

Phosphorus  ..  .  . 

•o?3 

.106 

.167 

.190 

.103 

.198 

.092 

.116 

The  effect  of  remelting  upon  the  silicon,  sulphur, 
manganese,  and  phosphorus  is  well  shown  in  Tables 
73,  74,  and  76.  We  find  the  results  are  all  in  line  with 
the  varied  experience  of  those  who  have  kept  close 
watch  of  remelts,  to  the  effect  that  silicon  and  man- 
ganese decrease  while  sulphur  and  phosphorus  increase. 
It  may  cause  some  surprise  that  more  silicon  was  not 
lost  or  sulphur  added  than  shown  by  the  four  continu- 
ous remelts  in  heats  Nos.  9,  10,  n,  and  12,  Table  73. 
The  author  accounts  for  this  in  that  the  metal  was  held 
in  the  cupola  but  a  short  time,  compared  to  that  gen- 
erally occupied  in  ordinary  shop  practice.  The  longer 
heated  or  semi-molten  iron  remains  in  contact  with 
incandescent  fuel  or  is  exposed  to  gases,  the  more 
sulphur  will  be  absorbed  —  up  to  the  limit  of  the  iron's 


342 


METALLURGY    OF    CAST    IRON. 


affinity  for  it.  The  reverse  is  true  of  silicon,  as  the 
longer  the  iron  is  exposed  to  the  effects  of  high  heat 
and  blast,  the  more  silicon  is  lost. 

STEELY  IRON  CASTINGS. 

Remelting  steel  requires  longer  time  to  fuse  than 
cast  iron,  as  will  be  seen  by  Table  No.  75,  page  340, 
in  which  heats  Nos.  21,  22,  and  23  are  continuous 
remelts  of  the  same  metals.  The  steel  was  a  "  riser- 
head  "  piece  of  scrap  that  was  moulded  to  make  a 
single  piece  of  cast  iron  of  the  same  form,  so  that  con- 
ditions as  to  form  and  weight  could  be  the  same  for 
both  metals  in  making  the  comparative  fusing  test 
shown.  Heats  24,  25,  26,  and  27  are  two  remelts  of 
different  quantities  of  cast  iron  and  steel  metals,  hav- 
ing similar  composition,  as  will  be  noted  by  referring 
to  columns  T  and  U,  Table  76,  page  341. 

Heats  24  and  26  had  the  metals  in  scrap  form  as 
nearly  alike  in  size  and  bulk  as  they  could  be  roughly 
made,  and  when  melting  they  ran  into  moulds  to  give 
blocks  2^  X4x6  inches,  so  as  to  insure  a  uniform  size 
of  stock  for  making  the  comparative  heats  25  and  27. 
Heat  28  was  a  remelt  of  the  blocks  obtained  from  heats 
25  and  27.  In  this  heat,  it  will  be  noticed,  the  iron 
and  steel  came  down  closely  together.  The  reason 
the  closing  time  is  not  shown  is  on  account  of  stopping 
up  the  tap  holes  after  the  iron  had  started  to  run,  with 
a  view  to  catching  metal  in  a  hand  ladle  to  pour 
shrinkage  and  contraction  tests  (see  page  410),  which 
left  the  matter  too  indefinite  to  record  the  time  of 
actually  finishing  first,  although,  as  near  as  we  could 
see  or  judge,  they  ended  closely  together.  Table  75 


COMPARATIVE    FUSIBILITY    OF    FOUNDRY    METALS.     343 

shows  that  the  more  we  remelt  steel  scrap  the  less 
difference  exists  in  the  iron  starting  and  closing  ahead 
of  the  steel.  This  is  due  to  the  fact  that  remelting 
steel  raises  its  total  and  combined  carbon  and  at  the 
same  time  we  find  that  steel  remelts  will  be  very 
spongy  or  filled  with  gas  or  blow-holes,  which  increase 
more  in  size  and  number  with  each  successive  heat, 
thus  causing  the  steel  product  to  be  very  porous  and 
thereby  permitting  the  heat  to  better  penetrate  its 
body  and  bring  it  quicker  to  a  fluid  state. 

Table  76  shows  the  folly  of  trying  to  remelt  steel 
and  obtain  from  it  the  original  metal,  as  can  be  closely 
done  with  cast  iron.  Nothing  has  led  founders  on 
more  wild-goose  chases  than  giving  ear  to  some  of  the 
high-sounding  claims  made  for  remelts  of  steel  or  its 
mixture  with  cast  iron.  It  is  true  that  steel  scrap 
mixed  with  cast  iron  can  strengthen  the  latter  to  a 
limited  degree,  but  the  extreme  claims  some  make  for 
its  mixture  with  cast  irons  are  erroneous  and  unfounded. 
We  have  no  metal  that  will  deteriorate  from  its  orig- 
inal state  by  reason  of  remelting,  so  much  as  steel 
scrap.  The  action  taking  place  in  remelting  steel  in 
a  cupola  increases  the  carbon  in  the  metal,  as  shown 
in  Table  76.  We  find  that  the  first  remelt  raised  the 
carbon  from  .60  to  1.48;  the  second  sent  it  up  to  2.74, 
and  the  third  to  3.05  —  an  increase  in  either  of  these 
three  remelts  sufficient  to  show  that  we  are  very  far 
from  retaining  anything  like  the  original  steel  in  any 
remelts  in  a  cupola  which  compels  the  steel  to  be  in 
contact  with  the  fuel  from  which  it  absorbs  the  carbon 
with  avidity. 

When  steel  is  melted  in  a  reverberatory  or  air  fur- 
nace, in  mixture  with  cast  iron,  we  have  more  favor- 


344  METALLURGY    OF    CAST    IRON. 

able  conditions  because  of  its  being  possible  to  keep 
the  carbon  lower  and  the  better  to  add  other  metals, 
as  Spiegel  and  ferro-manganese,  which  alloy  with  the 
fluid  metal  without  having  their  original  properties 
destroyed  to  any  great  degree.  Tensile  strengths 
ranging  from  45,000  to  50,000  pounds  per  square  inch 
have  been  obtained  by  air  furnace  meltings  with  mix- 
tures of  iron,  steel,  etc.,  but  to  obtain  castings  equal 
to  those  of  steel  proper  we  must  have  them  cast  by 
regular  steel  founders.  Whenever  we  desire  to  improve 
the  strength  of  cast  iron  by  mixture  with  steel,  the 
lower  carbon  or  soft  steels  will  be  found  to  give  the 
best  results,  and  air  furnace  meltings  excel  those  of  a 
cupola,  especially  if  charcoal  irons  are  used.  In  mix- 
tures with  the  latter,  from  15  to  30  per  cent,  of  soft 
steel  scrap  may  often  be  advantageously  used.  For 
further  information  on  the  steel  question,  see  pages  265, 
267,  271,  272  and  276,  and  the"  Moulder's  Text-Book. " 

THE  MELTING  POINT  OF  CAST  IRON. 

The  following  is  an  extract  of  a  valuable  paper  which 
was  presented  by  Dr.  Richard  Moldenke  before  the 
Pittsburg  Foundrymen's  Association,  Oct.  24,  1898. 
This  extract  gives  a  description  of  the  pyrometer  which 
the  doctor  used  for  testing  the  temperature  of  molten 
metal,  etc.,  and  of  its  value  in  other  lines,  also  of  tests 
he  made  as  found  in  Tables  77  to  8 1.  In  looking  about 
for  a  pyrometer,  the  doctor's  attention  was  naturally 
directed  to  the  latest  and  admittedly  the  best  form  of 
a  pyrometer  for  very  high  temperatures  —  the  Le 
Chatelier.  In  referring  to  this  instrument  and  to  his 
tests,  the  doctor  says :  "  This  pyrometer  consists  essen- 


THE    MELTING    POINT    OF    CAST    IRON.  345 

tially  of  two  pieces  of  wire  of  a  slightly  varying  com- 
position, a  heating  of  the  junction  of  which  produces  a 
current  of  electricity  proportioned  to  the  degrees  of  heat 
applied.  The  amount  of  this  current  is  measured  by 
a  suitably  calibrated  galvanometer,  and  thus  we  can 
read  off  the  heat  at  any  convenient  distance  rapidly 
and  with  a  surprising  degree  of  accuracy. 

"  Unfortunately,  this  wonderful  instrument,  one  wire 
of  which  is  of  platinum,  the  other  of  an  alloy  of  plati- 
num and  10  per  cent,  of  the  rare  metal  rhodium,  cannot 
be  immersed  directly  in  the  melted  iron  —  there  would 
soon  be  an  end  to  this  expensive  thermo-couple.  The 
long  porcelain  tube  which  protects  it  when  used  in 
kilns  is  worse  than  useless  in  a  ladle  full  of  metal,  and 
so  at  the  suggestion  of  the  writer  the  Pittsburg  repre- 
sentatives, the  Vulcan  Mfg.  Co.  set  about  to  remedy 
the  matter  and  devise  some  protective  cover  which 
would  allow  experiments  of  this  kind  to  be  carried  out 
readily.  The  outcome,  while  not  having  the  advantage 
as  yet  of  an  extended  period  of  trial,  was  nevertheless 
so  happy  a  solution  that  it  is  presented,  for  the  first 
time,  with  the  hope  that  much  of  value  may  be  learned 
from  it,  not  only  in  our  daily  work  but  also  in  connec- 
tion with  the  many  intricate  problems  still  before  us 
which  await  solution  at  the  hands  of  those  willing  to 
give  their  time  and  energy  to  such  an  exacting  study. 

"Fig.  64  shows  a  section  through  the  instrument. 
The  platinum  wire  will  be  noticed  running  from  the 
terminal  box  through  an  iron  pipe  ending  at  the  inner 
side  of  the  point  of  the  clay  tip.  Here  is  the  button 
made  by  the  fusion  to  the  other  wire  of  platinum  and 
rhodium  alloy  which  runs  back,  parallel  to  the  platinum 
wire,  to  the  terminal  box.  Both  wires  are  covered 


FIG.    64. — SECTION  THROUGH   PYROM- 
ETER. 


FIG.    6g. — TWO   FORMS  OF  LE  CHATELIER 
PYROMETER. 


THE    MELTING    POINT    OF    CAST    IRON. 


347 


with  asbestos  to  insulate  them  from  each  other  and 
from  the  iron  frame,  as  well  as  to  serve  as  a  protection 
in  case  the  tip  breaks  while  in  the  molten  iron.  The 


FIG.    66.— METHOD   OF   USING   IN    LADLE. 

interchangeable  connection  holding  the  clay  tip  allows 
it  to  point  out  straight  for  use  in  small  ladles  or  in 
experimenting,  or  it  may  come  down  at  right  angles 
for  taking  temperatures  in  large  ladles  full  of  metal. 


METALLURGY    OF    CAST    IRON. 


A  third  form,  not  completed  in  time  for  illustration 
purposes,  has  a  ball  and  socket  joint  which  allows  the 
tip  to  stand  out  at  any  angle.  A  movable  shield  lined 
with  asbestos  protects  the  hand. 


FIG.    67. — APPARATUS   FOR   DETERMINING  THE  MELTING  POINT   OF  CAST 
IRON  —  SIDE   VIEW. 

"Fig.  65  shows  two  of  the  styles  of  the  pyrometer, 
and  Fig.  66  the  method  of  using  the  angular  form.  In 
the  terminal  box  are  placed  the  connections  which 
allow  wirps  of  any  convenient  length  to  run  through 
the  handle  and  connect  with  the  galvanometer.  The 
galvanometer  itself  is  a  *  D'Arsonville,  specially 


THE    MELTING    POINT    OF    CAST    IRON.  349 

gotten  up  and  calibrated  for  industrial  purposes.  The 
original  form  with  the  reflecting  mirror,  and  capable 
of  reading  to  one-half  of  a  degree  at  these  high  tem- 
peratures, was  found  too  cumbersome  and  delicate  for 
factory  use. 

"The  sensitiveness  of  the  couple,  even  though  pro- 
tected by  a  refractory  material,  is  such  that  by  plung- 
ing it  cold  into  the  melted  iron  the  correct  reading  is 
obtained  in  one  minute  and  three-quarters.  When 
properly  heated  up  to  redness  beforehand,  however, 
this  time  is  reduced  to  not  many  seconds. 

"  It  would  be  beyond  the  scope  of  this  paper  to  show 
the  many  uses  to  which  such  an  instrument  can  be  put 
in  the  steel  and  iron  trade.  On  the  question  of 
annealing  alone  it  will  pay  for  itself  in  a  short  time. 

"  We  come  now  to  the  subject  matter  itself.  You 
will  all  remember  the  recent  discussion  on  the  melting 
of  white  and  gray  irons,  Mr.  West's  elaborate  experi- 
ments confirming  our  daily  experience.  Yet  the  cor- 
rectness of  the  conclusions  were  questions,  and  while 
the  peculiar  phenomena  observed  in  the  behavior  of 
carbon  with  iron  make  any  positive  statements  rather 
hazardous,  yet  the  melting  down  of  a  lump  of  iron, 
and  taking  its  temperature  while  doing  so,  should 
stand  as  a  final  determination  of  its  melting  point  as 
viewed  from  the  entirely  practical  side  of  the  question. 
This  is  the  consideration  we  have  to  deal  with  daily 
in  cupola  and  furnace. 

"The  material  experimented  with  was  gathered  for 
several  years,  some  of  it  being  furnished  by  Mr.  Jos. 
Seaman,  Mr.  Thos.  D.  West,  and  Mr.  J.  E.  McDonald, 
members  of  this  association,  and  the  especially  interest- 
ing alloys  by  Mr.  R.  McDonald,  of  the  Crescent  Steel  Co. 


350  METALLURGY    OF    CAST    IRON. 

'  *  There  were  forty-eight  pig  irons,  embracing  both 
Foundry  and  Bessemer  brands  as  well  as  softeners, 
made  with  coke  and  with  charcoal,  both  cold  and  warm 
blast.  Seven  of  the  cast  irons  were  of  the  shape  seen 
at  A,  Fig.  67,  being  melted  right  from  the  tip.  The 
balance  of  the  fifteen  specimens  were  of  the  sand  and 
chill  rolls  made  by  Mr.  West  in  his  recent  experi- 
ments.* Two  steels  and  nine  alloys  of  chromium, 
tungsten,  and  manganese,  with  iron,  complete  the  list 
of  seventy-three  specimens. 

* '  The  melting  was  done  in  an  assay  furnace  converted 
for  the  time  into  a  cupola.  Fig.  68  gives  a  front  view 
of  it  while  in  full  operation.  A  jet  of  steam  entering 
the  stack  in  the  side  near  the  top  induced  the  blast, 
the  air  being  drawn  in  all  around  the  bottom.  In  this 
form  it  is  really  the  '  Herberz  '  cupola  of  European 
fame  and  excellent  for  small  diameters.  A  hole  was 
broken  into  the  wall  just  below  the  charging  door, 
which  must  be  kept  closed  when  not  used.  This  hole 
allows  the  introduction  of  the  pieces  of  pig  iron,  etc. 
After  heaping  up  enough  coke  to  last  for  some  time, 
the  piece  of  pig  iron  (of  full  section  and  about  five 
inches  long),  was  driven  into  the  bed,  surrounded  by 
incandescent  coke,  and  the  opening  closed  with  a  tile. 
After  it  was  red  hot  the  tile  was  removed,  the  pyrom- 
eter inserted  and  pushed  against  the  center  of  the 
pig  where  the  borings  were  taken  for  the  analysis. 
The  temperature  as  registered  by  the  pyrometer  rose 
rapidly,  then  more  slowly,  remaining  stationary  while 
the  iron  melted  slowly.  Then  as  the  point  finally 
became  uncovered  the  temperature  jumped  up,  going 

*  This  refers  to  the  experiments  seen  on  pages  332  to  339. 


THE    MELTING    POINT    OF    CAST    IRON.  351 

above  2,600  degrees  F.     In  this  way  the  results  noted 
in  the  tables  below  were  obtained. 

"It  took  much  patience,  a  loss  of  a  few  samples,  and 
a  number  of  broken  tips  to  accomplish  all  this,  but  on 
the  whole  the  results  given  are  as  good  as  could  be 
gotten  under  the  conditions  prevailing.  The  coke 
burning  up  would  let  the  iron  drop  a  little,  and  a  fail- 
ure to  adjust  the  pyrometer  to  suit  (the  opening  being 
closed  by  a  piece  of  sheet  iron,  to  prevent  undue  cool- 
ing by  air  drawn  in),  meant  a  break  in  the  tip,  which, 
while  not  affecting  the  results,  caused  subsequent  delay 
and  trouble. 

* '  The  following  general  observations  were  made. 
The  white  irons  held  their  shape,  the  iron  running 
from  the  sides  and  bottom  freely,  leaving  smooth  sur- 
faces. The  gray  irons  became  soft,  dropped  in  lumps, 
leaving  a  ragged  surface.  Ferro-manganese  samples 
became  soft  and  mushy,  exhibiting  a  consistency  of 
putty  before  finally  running  down.  Ferro-tungsten 
behaved  in  the  most  marked  way.  As  it  melted  it 
acted  like  white  iron,  but  instead  of  chilling  quickly  it 
ran  through  the  coke,  coming  down  the  spout  in  thin 
streams  like  white  hot  quicksilver,  only  setting  after 
collecting  in  a  pool  in  the  pan  of  sand.  (The  above  de- 
scription of  melting  points  of  white  and  gray  irons 
was  verified  by  other  members,  though  under  different 
conditions.)  The  cupola  was  fluxed  heavily  with  fluor 
spar  to  take  care  of  the  ash,  for  it  was  a  case  of  a 
furnace  full  of  incandescent  coke  and  only  one  piece 
of  iron  in  it. ' ' 

The  following  tables  give  the  results.  For  melt- 
ing points  of  other  metals  than  shown  in  this  chapter, 
see  Table  134,  page  593. 


352 


METALLURGY    OF    CAST    IRON. 


TABLE    77. — PIG    IRONS. 


o 

bo+J 

f! 

3  . 

~  c 
u 

Graphite. 

Silicon. 

Manganese. 

Phosphorus. 

Sulphur. 

i 

203o°F. 

3-98 

.14 

.10 

.220 

•037 

2 

2040 

3-90 

,-  . 

.28 

.11 

.216 

.044 

3 

2040 

3-74 

.14 

•38 

.16 

.172 

.032 

4 

2070 

3-70 

.26 

.09 

.198 

•033 

i 

2100 
2040 

3-52 
3.48 

•54 

1 

-.20" 
•09 

.200 
.249 

.036 
.040 

7 

2055 

3-22 

".'68 

.69 

.142 

.038 

8 

2010 

3-21 

.20 

•45 

.18 

.  1  98 

•037 

9 

2  1  10 

2.28 

I.I4 

.42 

•  13 

l£c 

.026 

10 

2140 

2.27 

1.80 

•45 

1.  10 

1465 

•032 

ii 

2150 

2.23 

1.58 

.42 

.16 

•415 

•°45 

12 

2170 

1.96 

I.QO 

•75 

•63 

•  .097 

.028 

13 

2170 

1-93 

I  69 

•52 

.16 

.760 

.036 

14 

2170 

1.87 

1:85 

•56 

.46 

•713 

.027 

15 

2150 

1.84 

i-95 

•3o 

•34 

•:75 

.022 

16 

2190 

1.72 

2.17 

1.88 

•54 

.446 

.028 

17 

220O 

1.69 

2.40 

1.81 

•49 

1.602 

.060 

18 

2230 

1.71 

2.08 

2.02 

•39 

•632 

.062 

19 

2190 

1.49 

2.26 

2-54 

•50 

•349 

.038 

20 

2210 

1.48 

2.30 

I.4I 

i-39 

.168 

•°33 

21 

2190 

1.47 

2.63 

.89 

.48 

.164 

•037 

22 

2190 

1.36 

2.41 

1.65 

•32 

.160 

•038 

23 

2210 

1.31 

2.70 

1-25 

.76 

.170 

.022 

24 

2210 

1.31 

2.40 

1.69 

.46 

•085 

•039 

25 

2230 

1.24 

2.68 

•65 

.26 

.201 

.020 

26 

223O 

1.23 

2.70 

1.20 

•37 

.299 

.022 

27 

2230 

1.  12 

2.66 

I-I3 

.24 

.089 

.027 

28 

2200 

.90 

3-07 

1.09 

•33 

.176 

.014 

29 

2230 

.87 

3-10 

1-34 

.42 

.158 

.030 

30 

22  IO 

.84 

3-07 

2.58 

•47 

2.124 

.051 

31 

2260 

•83 

3-26 

1-97 

•59 

.210 

.018 

32 

2230 

.80 

3-22 

1.30 

•59 

.172 

.042 

33 

2250 

.80  ' 

3-16 

1.29 

•50 

.218 

.O2O 

34 

2250 

.80 

-    2.89 

2.21 

•25 

.411 

.041 

35 

2250 

.67 

3.60 

1-32 

.20   ' 

.205 

.020 

36 

224O 

•59 

'     3-15 

I.50 

.61 

.094 

.032 

37 

2230 

•47 

-     2.84 

2.19 

•65 

I.5I8 

.042 

38 

2250 

•38 

'   3-43 

2-44 

'•57 

.422 

.048 

39 

2250 

•35 

3-44 

2.07 

.28 

.448 

•°39 

40 

220O 

•35 

3-70 

3-29 

.82 

.501 

•038 

41 

2260 

.24 

3.48 

2.54 

•30 

060 

.020 

42 

2280 

•13 

3-43 

2.40 

.90 

.082 

•032 

TABLE    78.  —  SOFTENERS,   FERROSILICONS,   AND    SILICO    SPIEGEL. 

43 

2190 

3.38 

•37 

12.30 

16.98 

44 

2040 

1.82 

•47 

12.  OI 

1.38 

45 

2090 

2.17 

10.96 

1-34 

46 

2155 

i-35 

1.  60 

9.40 

•32 

47 

2145 

1.57 

1.36 

8-93 

•39 

48 

2170 

1.77 

i.So 

4.96 

•39 

THE    MELTING    POINT    OF    CAST    IRON. 


353 


TABLE    79. CAST   IRONS. 


I 

Melting 
Point. 

Com. 
Carbon. 

Graphite. 

Silicon. 

rt 
bCdJ 
C  <fi 

a  v 
%a 

en 

A 

£»o, 

PH  ^ 

Sulphur. 

Remarks. 

49 
53 

2000°F 

1990 

4.67 
4.20 

•03 

.20 

•57 
•63 

.22 

•33 

.266 
•254 

.044 
.040 

Cast  into  chill  roll  (Mr.  West) 
Cast  into  chill  roll  (Mr.  West) 

51 

20IO 

4.08 

•89 

.06 

.287 

.040 

Cast  into  dry  sand. 

52 

53 
54 
55 
56 

2OOO 
2030 
2030 
2040 
2170 

3-90 

3-62 
3.48 
3-40 
•63 

"".16 

2.27" 

•75 
.72 
•47 
.42 
1.46 

.66 
.14 
.09 
.07 
•50 

.240 

•93 
.190 
.196 
.092 

.030 
.026 
.032 
.029 
.032 

Ca.)t  into  chill  roll  (Mr.  West) 
Cast  into  dry  sand. 
Cast  into  dry  sand. 
Cast  into  dry  sand. 
Cast  into  dry  sand. 

57 

2210 

.60 

3.16 

•59 

•25 

.271 

.048 

No.  48  in  sand  rolls  (Mr.  West) 

58 
59 

2250 

2240 

•57 

.22 

2:66 

.66 
1.69 

•3i 

•47 

•237 
.274 

.040 
•037 

No.  49  in  sand  rolls  (Mr.  Westj 
Cast  into  dry  sand. 

60 

22.50 

.20 

2.90 

•  75 

.66 

.248 

.030 

No.  51  in  sand  rolls  (Mr.  West) 

61 

2260 

•17 

3-57 

2.09 

•43 

.272 

.042 

Cast  into  green  sand. 

62 

208O 

1.95 

1.28 

1.64 

.98 

Re-melted  ferro-silicon  No. 

5,  cast  into  chill  roll  (Mr. 

West). 

63 

2080 

1.81 

1.36 

11.70 

I.OO 

Re-melted  ferro-silicon   No. 

5,  cast  into  sand  roll  (Mr. 

West). 

"For  a  better  comparison  of  the  melting-  points  of  the 
same  irons  cast  into  sand  and  into  chills,  as  made  by 
Mr.  West,  the  following-  table  is  subjoined : 

TABLE  80. 


No. 

Combined 
Carbon. 

Graphite. 

Fracture. 

Melting 
Point. 

57 
49 

1.60 
4-67 

3-i6 
•03 

Gray 
White 

22IO°F. 
2000 

Same  ladle. 

58 
50 

1-57 
4.20 

2.90 

.20 

Gray 
White 

2250 
1990 

Same  ladle. 

60 

1.20 

2.90 

Gray 

2250 

52 

3-90 

.16 

White 

2000 

Same  ladle. 

TABLE  8l. —  ALLOYS  AND  STEEL. 


be 

•  .5+j 
2  g 

| 

1 

Isi 

oj 

li 

Remarks. 

s 

s£ 

U 

35 

3s 

0S 

£* 

64 

2450°F. 

1.18 

.21 

•49 

Steel. 

65 

2350 

1.32 

.29 

1.27 

3-40 

6.21 

Steel. 

66 
67 

2280 
2240 

39-02 
11.84 

Ferrotungsten. 
Ferrotungsten. 

68 

.     2255 

5.02 

'1-65 

81.40 

Ferromanganese. 

69 
70 

2210 
2400 

6.48 
6.80 

.14 

44-59 

62.70 

Ferrom  a  nganese. 
Ferrochrom. 

71 

22"io 

6.40 

19.20 

Fe  r  roc  h  r  om  . 

72 

2260 

i.  20 



19.10 

Ferrochrom. 

73 

2180 

1.40 

5-40 

Ferrochrom. 

354  METALLURGY    OF    CAST    IRON. 

The  tables  of  the  pig  and  cast  irons  have  been 
arranged  according  to  their  combined  carbon  contents, 
for  it  is  evident  that  with  few  exceptions  the  melting 


FIG.    68. — APPARATUS   FOR   DETERMINING    THE    MELTING   POINT   OF   PIG 
IRONS,  ETC. —  FRONT  VIEW. 

r 


THE    MELTING    POINT    OF    CAST    IRON.  355 

points  increase  as  the  combined  carbon  goes  down, 
this  being  the  case  independent  of  the  amount  of 
graphite  present.  One  could  hardly  expect  anything 
else,  for  that  matter,  gray  cast  iron  being  really  a  steel 
with  a  lot  of  mechanically  mixed  graphite,  and  white 
iron  a  combination  of  carbon  with  iron.  Alloys  melt 
at  a  lower  temperature  than  any  of  their  constituents, 
and  so  also  white  iron  —  really  an  alloy  of  carbon  or 
some  carbides  of  iron  with  iron  —  should  melt  sooner 
than  the  purer  iron  in  the  gray  variety. 

' '  The  fact,  however,  that  steel  melts  at  a  much  higher 
temperature  than  the  grayest  of  irons  in  the  table, 
shows  that  there  are  other"  considerations  not  to  be 
overlooked  in  studying  the  molecular  physics  of  cast 
iron.  The  principal  reason  for  this  lowering  of  tern } 
perature  is  the  supposed  solution  of  the  graphite  in  the 
iron  before  actual  melting  takes  place.  To  what 
extent  this  occurs  and  under  what  circumstances  is  not 
known,  but  may  account  for  the  difference  in  the 
melting  points  of  steel  and  gray  iron. 

'  *  Again,  in  melting  steel  in  the  cupola  commercially, 
an  absorption  of  carbon  from  the  fuel  takes  place,  the 
melting  point  is  doubtless  lowered  a  little,  and  the 
results  obtained  are  tangible,  even  though  care  must 
be  taken  to  get  the  whole  of  the  charge  down  before 
pouring.  In  the  air  furnace  the  steel  absorbs  carbon 
by  contact  with  the  pig  iron  charged  and  melts  off,  the 
wasting  of  wrought  iron  or  steel  poking  bars  used  for 
rabbling  giving  evidence  of  this  occurrence. 

*  *  The  writer  is  especially  pleased  to  see  the  full  corrob- 
oration  of  Mr.  West's  elaborate  experiments  with  the 
melting  of  white  and  gray  irons.  The  contrast  is 
remarkably  sharp,  and  on  the  whole  it  shows  us  that 


356  METALLURGY    OF    CAST    IRON. 

science  and  practice  go  hand  in  hand  admirably,  no  mat- 
ter what  the  field  may  be.  Whatever  theories  may  de- 
velop regarding  the  melting  of  iron,  whatever  the  effect 
of  high  or  low  phosphorus,  silicon,  manganese,  and 
sulphur  may  be  shown  to  be  on  the  melting  point  of 
an  iron  eventually  (the  present  series  of  irons  not 
being  well  enough  adapted  for  this  phase  of  the  ques- 
tion), the  results  here  given  are,  it  is  hoped,  of  suffi- 
cient value  to  stimulate  further  research  of  practical 
value  to  the  founders  of  cast  iron. ' ' 


CHAPTER  XLVII1. 

ALUMINUM  ALLOYS  IN   FOUNDING. 

Aluminum  was  discovered,  it  is  claimed,  by  Fred- 
erick Wohler,  a  German  professor,  in  1827;  but  to  St. 
Clair  Deville,  a  Frenchman,  belongs  the  honor  of  be* 
ing  the  founder  of  the  aluminum  industry.  The  first 
article  made  of  this  metal,  it  is  said,  was  in  compliment 
to  Louis  Napoleon,  the  benefactor  of  Deville,  and  was 
a  baby  rattle  for  the  infant  Prince  Imperial.  About 
ten  years  ago  it  was  thought  that  aluminum  would 
revolutionize  all  metallurgy,  but  usage  and  practical 
tests  have  more  closely  defined  its  sphere.  We  find 
that  to-day  its  adoption  is  chiefly  limited  to  the  manu- 
facture of  fancy  commercial  wares,  also  alloys  of  brass 
and  bronze,  the  former  being  extended  to  an  industry 
employing  a  large  number  of  wage  earners. 

In  the  first  days  of  the  aluminum  industry  great  dim 
culty  was  experienced  in  obtaining  perfect  castings 
with  aluminum  alloys.  It  was  seldom  that  a  sound 
casting  could  be  obtained.  The  Cowles  Electric 
Smelting  and  Aluminum  Co.,  of  Lockport,  N.  Y.,  one 
of  the  first  to  manufacture  aluminum  alloys,  etc. ,  en- 
gaged the  author,  in  the  year  1886,  to  go  to  Lockport 
for  a  short  time.  The  author's  experience  in  this 
foundry  resulted  in  finding  aluminum,  as  an  alloy, 
very  wild  in  its  actions,  and  that  the,  greatest  difficulty 
might  always  be  expected  with  it  in  obtaining  strictly 


358  METALLURGY    OF    CAST    IRON. 

aluminum  bronze  castings.  I  have  seen  a  pot  of  alu- 
minum bronze  kept  for  twelve  hours  in  a  furnace  be- 
fore tests  had  proven  it  to  be  the  grade  of  metal  de- 
sired, and  the  chances  were  that,  had  it  proven  all 
right,  if  a  second  test  had  been  taken  a  few  moments 
later  it  would  have  shown  that  a  great  change  had 
taken  place  in  the  metal.  The  author  succeeded  in 
obtaining  sound  castings  from  some  very  complex  pat- 
terns, but  he  was  not  able  to  make  any  formula  or  di- 
rections for  a  mixture  which  would  insure  like  desired 
results  every  melting,  as  far  as  physical  tests  were 
concerned.  It  must  be  remembered  that  at  this  time 
pure  aluminum  was  not  obtained  for  commercial  pur- 
poses, as  it  is  at  the  present  day.  Then  it  was  only 
obtainable  by  being  alloyed  with  iron  or  copper  con- 
taining from  about  5  to  20  per  cent,  of  aluminum.  To 
obtain  5  to  20  per  cent,  of  aluminum  in  any  alloy  of  cop- 
per or  iron,  80  to  95  per  cent,  of  these  latter  elements 
had  to  be  melted  in  mixture  with  what  was  in  the  pot  in 
order  to  have  a  chance  of  securing  the  grade  wanted. 
Since  the  advent  of  the  Pittsburgh .  Reduction  Co. , 
about  the  year  1890,  aluminum  is  obtainable  for  com- 
mercial purposes  in  a  free  state,  without  being  alloyed 
with  any  other  metal.  This  has  proved  more  satis- 
factory in  enabling  a  formula  to  be  utilized  to  the  end 
of  securing  like  results  at  all  times,  but  has  not  re- 
moved the  difficulty  of  obtaining  perfect  castings  of 
aluminum  bronze  alloys. 

The  author  has  tried  aluminum  in  mixture  with  cast 
iron.  In  some  cases  it  would  slightly  improve  the 
strength,  and  again  it  would  weaken  the  iron.  The 
influence  of  aluminum  is  similar  to  that  of  silicon. 
Where  the  combined  carbon  is  high,  it  will  lower  it  so 


ALUMINUM    ALLOYS    IN    FOUNDING.  359 

as  to  make  the  iron  of  a  softer  nature.  Where  the 
graphite  is  highest,  it  will  close  the  grain  and  give  the 
iron  a  leaden  color  and  generally  decrease  its  strength ; 
whereas  the  reverse  will  generally  be  true  if  the  com- 
bined carbon  has  overreached  that  point  which  would 
afford  the  iron  the  greatest  strength.  On  a  whole, 
aluminum,  as  far  as  strength  is  concerned,  is  only  of 
value  in  use  with  very  hard  grades  of  iron,  or  those 
exceeding  1.65  in  combined  carbon.  The  percentage 
of  aluminum  which  I  used  would  range  from  one-quar- 
ter of  one  per  cent,  to  i  ^  per  cent.  The  aluminum 
was  placed  in  the  bottom  of  the  ladle  and  the  molten 
metal  poured  over  it.  I  found  this  plan  better  than 
throwing  it  into  the  molten  metal  after  the  ladle  had 
been  filled.  In  both  cases  the  metal  would  always  be 
stirred  with  a  rod  to  assist  in  mixing  the  metals. 
Aluminum  will  increase  the  fluidity  of  molten  metal, 
but  to  obtain  the  best  results  in  this  line  it  must  be 
used  with  care  and  judgment.  To  secure  the  greatest 
fluidity  by  means  of  aluminum  depends  upon  the  per- 
centages of  the  elements  which  compose  the  iron  de- 
signed to  make  it  soft  or  hard.  The  harder  the  iron 
the  more  aluminum  can  be  used  to  obtain  the  greatest 
degree  of  fluidity.  With  soft  grades  aluminum  can 
make  the  metal  sluggish,  with  excessive  dross  on  its 
surface,  just  as  can  be  the  case  by  having  too  much 
silicon  in  a  mixture. 

While  the  way  in  which  aluminum  will  generally 
work  in  affecting  the  different  percentages  of  carbon 
in  iron  are  above  outlined,  still,  on  the  whole,  it  is 
very  erratic  and  will  often  act  contrary  to  expectations. 
One  peculiarity  about  aluminum  alloyed  with  iron  is 
displayed  where  two  ladles  are  used  to  pour  a  mould, 


360  METALLURGY    OF    CAST    IRON. 

often  showing  a  ' '  cold  shut ' '  or  bad  union  of  iron  at 
the  point  where  the  streams  of  metal  from  the  respec- 
tive ladles  meet  each  other.  Aluminum  is  also  alloyed 
with  silver,  nickel,  tungsten,  manganese  and  silicon, 
as  well  as  copper,  iron  and  steel. 

Pure  aluminum  is  the  lightest  of  all  known  metals, 
except  magnesium.  Its  specific  gravity  is  from  2.6  to 
2.7  and  it  melts  at  about  1500  degrees  F.  It  is  white 
in  color,  of  a  soft  nature,  possessing  a  strength  of  about 
one -third  that  of  wrought  iron.  While  pure  alumi- 
num melts  at  1 500  degrees  F. ,  still  its  reduction  in  the 
blast  furnace  from  any  ore  is  such  as  not  to  alloy  with 
the  iron  to  any  extent.  Why  the  iron  will  not  take  up 
aluminum  to  any  degree  in  the  process  of  reducing 
ores  is  a  question  still  unanswered.  It  is  a  test  that 
shows  that  iron  possesses  but  little  affinity  for  alumi- 
num, so  far  as  proving  of  any  practical  value  to  .iron 
founding  is  concerned.  In  all  the  author's  experience 
with  aluminum  in  cast  iron  he  cannot  say  that  he  ever 
knew  it  to  accomplish  anything  which  could  not  be 
obtained  by  means  of  silicon,  which  is  much  cheaper 
than  aluminum. 


*  For  the  specific  gravity  and  weight  per  cubic  inch  of  other 
metals,  see  Table  136,  page  593. 


PART  III. 


CHAPTER   XLIX. 

METHODS  FOR  MELTING  CAST  IRON  TO 
TEST  ITS  PHYSICAL  QUALITIES. 

Owing  to  the  impracticability  of  judging  pig  metal 
by  its  fracture,  the  author  has  thought  a  Chapter  on 
methods  for  melting  small  quantities  to  test  its  phys- 
ical qualities  would,  in  many  cases,  prove  of  value,  es- 
pecially where  a  founder  was  not  in  position  to  utilize 
chemistry. 

There  are  three  methods  by  which  iron  can  be 
melted  for  testing  its  physical  properties.  One  is  to 
take  the  regular  "  heats  "  mixture,  another  to  have  a 
very  small  cupola  expressly  for  melting  light  "heats," 
weighing  from  50  to  500  pounds,  and  the  third  by 
means  of  a  furnace  and  crucible  similar  to  the  prin- 
ciple used  for  melting  brass,  etc.  By  using  metal 
from  the  first,  we  can  at  any  period  of  a  heat  tell  the 
physical  properties  of  any  mixture  poured  at  that  time. 
By  using  the  small  cupola  we  can,  by  proportioning  a 
mixture  in  light  charges,  obtain  a  good  approximate 
knowledge  of  the  product  to  result  from  a  like  mixt- 
ure in  regular  "heats,"  and  also  where  there  are  sev- 
eral brands  or  grades  of  pig  metal,  each  can  be  tested 
separately,  to  ascertain  its  physical  properties,  thus 
enabling-  one  to  detect  any  brands  that  might  be  de- 
ceptive in  appearance  and  thereby  contaminate  and 


METHODS  FOR  MELTING  TO  TEST  CAST  IRON.  363 

prevent  physical  results  being-  obtained  from  any 
desired  mixture.  By  melting-  in  the  crucible,  we  can 
closely  tell  the  physical  properties  in  respect  to  what 
the  chemical  elements  would  define  it  in  the  original 
state,  when  not  affected  by  the  sulphur,  etc.,  in  fuel, 
but  not  what  it  would  be  when  remelted.  Why  this 
is  so  involves  elements  most  essential  for  the  founder 
to  understand  and  are  treated  further  in  Chapter 
XLV. 

Melting  a  mixture  in  a  crucible  with  the  expectation 
of  obtaining  tests  to  denote  what  the  physical  qualities 
of  a  regular  cupola  mixture  would  be,  is  impractical. 
These  can  be  told  with  fairness  by  taking  tests  from 
the  regular  cupola.  Small  cupolas  ranging  from  fifteen 
to  twenty  inches  inside  diameter  can  often  be  well 
used  to  test  single  brands  or  grades  or  mixtures  not 
having  over  four  different  kinds  of  iron.  As  there  are 
cases  where  some  would  like  to  use  a  small  cupola 
for  crucible  melting  also,  I  have  studied  to  the  point 
of  combining  the  two,  and  as  a  result  present  the  fol- 
lowing original  device  or  small  cupola,  as  seen  in  Fig. 
69,  next  page.  This  cupola  can  be  erected  in  any  out- 
of-the-way  place,  or  by  the  side  of  a  regular  "  heat  " 
cupola,  so  that  the  flue  A  can  be  attached  to  head  off 
the  sparks,  etc.,  when  used  as  a  cupola,  without  risk  of 
setting  anything  on  fire,  should  there  be  any  danger 
of  this;  if  not,  then  the  cover  B  could  be  dispensed 
with  and  the  flame,  etc.,  permitted  to  pass  out  at  the 
top.  B  is  a  cover  made  of  cast  iron,  and  having  prick- 
ers on  the  under  side  for  the  purpose  of  holding  a  daub- 
ing of  clay  to  prevent  the  heat  of  the  furnace  burning 
the  cover.  The  handle  D  is  for  convenience  in  lifting 
the  cover  on  and  off  when  desiring  to  change  or  take 


METALLURGY    OF    CAST    IRON. 


out  a  crucible.  The  staging  H  as  shown  is  placed  any 
height  to  suit  the  operator.  The  cupola  has  four 
tuyeres,  two  inches  in  diameter.  In  charging  to  run  a 
' '  heat, ' '  have  the  coke  ten  inches  above  the  tuyeres ; 

if  coal,  seven  inch- 
es   above     the 
,  __^  tuyeres.    The  fuel 
i—  should  not  be 
much  larger  than 
double    egg   size, 
and  the  bed  well 
burned  up  before 
the    first    iron    is 
charged.     On  the 
bed,  place  fifty  to 
one      hundred 
pounds    of     iron, 
which,  if  pig  iron, 
should  be  broken 
in  lengths  of  from 
~^\-  five  to  eight  inch- 
es.      If   the    pigs 
were  too  strong  to 
break    by    sledg- 
2     ing,  etc. ,  one-inch 
holes      could     be 
and    a 
to 

fracture.     Should 
more     than      100 


....  ^.-drilled 
~0''i££ii  punch      used 


FIG.   69. — WEST'S    COMBINED    CUPOLA   AND 
CRUCIBLE   FURNACE. 


pounds  require  melting,  charge  twenty  pounds  of  coke 
or  coal,  and  on  this  one  hundred  pounds  of  iron,  and  so 
continue  as  long  as  the  cupola  works  all  right.  With  a 


METHODS  FOR  MELTING  TO  TEST  CAST  IRO] 

slag-hole  as  at  E,  Fig.  69,  and  the  use  of  flux,  a  "  heat  " 
can  be  prolonged  to  run  several  hours.  If  lime  was 
used  for  a  flux,  about  four  pounds  to  every  one  hun- 
dred of  iron  charged  should  cause  the  slag  to  run  freely. 
We  are  only  entering  into  these  details  in  order  to  illus- 
trate the  fact  that  the  cupolas  can  be  used  for  heavier 
"heats"  than  test  bars  would  necessitate.* 

In  melting  with  a  crucible  in  the  cupola,  Fig.  69, 
use  a  size  like  No.  18  Dixon's  brass.  -In  preparing 
the  cupola  for  melting  with  crucibles,  put  in  a  sand 
bottom  within  two  inches  of  the  level  of  the  tuyeres. 
Have  a  bed  of  coke,  when  well  burnt  up,  ten  inches 
high,  and  on  this  set  the  crucible  charged  with  its 
burden  of  iron  to  be  melted.  Fill  all  around  between 
the  crucible  and  the  cupola  lining  with  small  coke, 
level  with  the  top  of  pot.  Cover  the  pot  over  with  a 
clay  cover,  which  can  be  formed  in  a  core  box  and 
rodded  the  same  as  one  would  a  dry  sand  core  to  pre- 
vent its  cracking,  or  the  bottom  of  an  old  crucible  can 
be  used.  The  smaller  the  iron  is  broken  the  more 
quickly  it  will  melt,  and  hence  the  easier  will  it  be  on 
the  pot  and  more  economical  in  fuel.  After  the  pot  is 
covered,  the  cover  D  is  placed  on  to  close  the  furnace. 
The  blast  is  now  put  on  the  same  as  if  iron  were  being 
melted  direct  in  a  cupola.  The  pressure  should,  for 
crucible  work,  range  from  two  to  three  ounces ;  for  cu- 
pola work,  four  to  eight  ounces  can  be  used,  and  such 
*  Should  any  desire  plans,  with  complete  specifications,  for  con- 
structing small,  permanent  cupolas,  ranging  from  twelve  inches 
to  eighteen  inches  diameter,  strictly  for  melting  light  ' '  heats ' ' 
without  crucible  arrangements,  we  would  refer  them  to  "Moulder's 
Text-Book,"  page  265,  and  in  the  same  work,  page  248,  will  be 
found  a  cheap  temporary  arrangement  for  melting  from  fifty  to 
one  hundred  pounds  of  iron. 


366  METALLURGY    OF    CAST    IRON. 

blast  can  often  be  supplied  from  a  blacksmith's  forge 
fan.  Should  it  be  desirable  to  run  steadily  all  day  for 
crucible  work,  the  breast  should  be  dug  out  about 
twice  during  the  "heat,"  and  the  ash  and  dross  pulled 
out,  so  as  to  leave  room  for  clean  fuel.  In  making  the 
breast  for  crucible  work,  have  it  formed  of  a  sand  that 
will  not  bake  or  cake  hard  and  larger  than  shown. 
This  will  permit  its  being  dug  out  readily. 

Should  it  not  be  desired  to  use  the  device  as  a  combina- 
tion furnace  and  cupola,  but  strictly  for  crucible  work, 
we  would  advise  sinking  the  same  in  a  pit,  and  in- 
stead of  using  the  regular  cupola  drop  bottom,  which 
goes  with  this  device,  have  the  bottom  consist  of  a  reg- 
ular grate,  with  an  ash  pit  six  inches  deep,  the  diam- 
eter of  the  grate.  Have  the  ash  pit  closed  air-tight, 
and  instead  of  admitting  the  blast  into  the  body  of  the 
furnace,  as  is  done  with  the  cupola  here  shown,  let  it 
pass  into  the  ash  pit  and  enter  the  furnace  through 
the  grates.  By  having  a  pit  three  feet  by  five  feet  and 
three  feet  deep  the  combination  cupola  and  furnace 
could  be  lowered  to  bring  the  staging  line  H  level 
with  the  floor.  This  would  make  it  more  convenient 
for  charging,  or  lifting  a  crucible  in  or  out,  and  by 
having  a  handy  step-ladder,  ready  access  can  be  had  to 
the  pit  for  "tapping  out"  or  cleaning  the  "  dump." 
For  raising  a  pot  of  metal  up  to  the  floor,  employ  a 
pair  of  tongs  similar  to  those  used  for  lifting  a  crucible 
out.  The  flue  A  should  be  lined  with  fire  brick  or  clay 
for  any  distance  the  outer  shell  could  be  heated  red 
hot  were  it  not  lined.  This  flue  should  be  well  bound 
with  stays  to  prevent  the  heat  cracking  it  open. 

As  very  few  founders  have  had  opportunity  for  ex- 
perience in  crucible  work,  we  will  detail  more  points 


METHODS  FOR  MELTING  TO  TEST  CAST  IRON.  367 

necessary  to  be  followed.  As  melting  progresses,  the 
fuel  around  the  sides  of  the  pot  will  settle  down. 
This  must  be  replenished  so  as  to  keep  the  fuel  about 
on  the  level  with  the  top  of  the  pot.  To  have  it  high- 
er at  the  first  would  be  an  advantage.  Judgment 
should  be  used  not  to  fill  in  fuel  when  the  pot  is  about 
ready  to  be  pulled  out,  as  this  will  tend  to  cool  the 
metal  and  prevent  the  free  use  of  the  tongs  in  grasp- 
ing the  pot  to  remove  it  from  the  furnace.  A' pot  will 
settle  more  or  less  in  the  fuel  and  it  may  be  necessary 
to  lift  it  up  several  times  so  that  the  fuel  from  arotlnd 
the  sides  can  settle  down  and  raise  the  pot,  after  which 
the  sides,  of  course,  would  require  fresh  fuel.  In 
charging  the  iron,  the  pot  may  not  hold  all  that  is  de- 
sired at  the  first  filling.  In  such  case,  additional  iron 
can  be  charged  as  fast  as  the  solid  melts  down.  The 
crucible  will  average  about  forty  heats,  if  handled  care- 
fully. The  least  moisture  in  a  pot  would  cause  it  to 
crack  in  the  fire.  It  must  be  thoroughly  dry  before 
being  used  for  a  "heat."  A  good  practice  is  to  place 
a  crucible  in  an  oven  for  several  days  before  using  it. 
While  it  is  essential  to  have  the  moisture  all  out  of  the 
pot,  it  is  also  well  to  never  permit  it  to  cool  off  sud- 
denly. If  after  a  heat  the  pot  is  set  back  in  the  fire  to 
cool  down  with  it,  its  life  will  be  prolonged.  Iron 
melted  in  a  crucible  will  be  found  to  possess  a  quiet 
appearance,  and  it  is  generally  not  so  hot  as  coming 
from  a  cupola.  In  operating  either  the  cupola  or  the 
crucible,  only  the  best  of  fuel  should  be  used,  and  all 
work  should  be  intelligently  manipulated. 


CHAPTER  L. 

JUDGING  OF  AND  TESTING  MOLTEN 
IRON. 

In  testing  iron  we  have  two  properties,  chemical  and 
physical,  to  which  we  might  add  the  phenomenon  of 
fusion.  An  experienced  eye  can  often  very  fairly  tell 
what  a  casting  will  be,  physically,  by  judging  the 
appearance  of  the  metal  when  running  or  at  rest  in  a 
ladle. 

In  many  cases  the  ability  to  judge  liquid  metal 
will  often  prove  of  value,  for  while  we  seldom  have 
means  for  changing  its  character  when  fluid,  we  can 
often  refrain  from  pouring  work  when  our  judgment 
asserts  that  a  metal  is  radically  wrong.  There  is 
this  much  that  can  be  said  of  re-melted  fluid  iron :  It 
will  rarely,  if  ever,  deceive  an  expert,  as  can  the  judg- 
ing of  iron  in  the  pig  before  being  melted.  We  can 
rest  assured  that  if  it  looks  radically  soft  in  a  liquid 
state,  it  will  not  prove  hard  in  a  solid  one,  and  vice 
versa. 

The  ordinary  moulder  can,  with  a  short  experience, 
tell  the  degree  of  fluidity,  or  whether  the  iron  is 
"  hot  "  or  "  dull."  Why  he  should  be  better  able  to 
do  this  than  judge  of  its  physical  qualities  when  mol- 
ten, is  mainly  due  to  present  practice  not  often  afford- 
ing means  to  change  or  correct  a  metal  that  might  not 
look  right.  The  degree  of  the  temperature  before 


JUDGING    OF    AND    TESTING    MOLTEN    IRON.  369 

being  poured  he  can  often  greatly  control,  and  hence 
the  advantage  of  practice  in  this  factor  causes  study  to 
train  the  eye,  which  very  soon  becomes  expert  in  de- 
ciding the  best  moment  at  which  to  pour  a  mould.  A 
like  study  of  the  molten  character,  combined  with  the 
temperature  in  a  fluid  state,  may  enable  the  moulder 
to  judge  as  well  in  one  case  as  the  other,  and  this 
should  be  practiced  more  than  it  is,  as  no  moulder  or 
founder  can  tell  when  a  knowledge  of  the  former 
would  not  be  as  valuable  as  the  latter. 

Judging  the  grade  of  metal  by  its  appearance  in  a 
fluid  state  is  often  done  by  experienced  founders,  and 
with  a  little  study  and  observation  the  following  de- 
scription may  often  enable  the  inexperienced  to  soon 
become  proficient  in  judging  molten  metal:  A  No.  i 
or  high  graphite  soft  iron  *  will  generally  present  a 
lively  vibration  of  different  colors  having  the  appear- 
ance of  coming  up  from  below  the  surface,  forming  an 
oxidized  crust.  This  crust  has  the  appearance  of  strug- 
gling to  break  away  from  alloys,  which  do  not  take 
kindly  to  being  associated  with  a  grey  or  soft  iron. 
When  No.  i  iron  is  slowly  cooling  down  from  a  high 
temperature  to  a  low  one,  it  will  often  be  unable  to 
hold  all  its  carbon  in  a  combined  state.  What  cannot 
be  retained  will  gradually  rise  to  the  surface  as  graph- 
ite in  the  form  of  a  scum  or  kish,  and  in  the  latter 
state  will  float  away  in  the  air,  often  covering  every- 
thing near  at  hand  with  thin  flakes  of  shining  mate- 
rial, looking  like  silver  lead  or  plumbago.  This  can 
properly  be  called  pure  carbon  freed  from  the  metal. 
About  blast  furnaces,  this  latter  phenomenon  can 
often  be  seen,  sometimes  so  active  that  the  employes 
will  be  covered  with  ' '  kish, ' '  making  them  look 

*This  refers  to  iron  possessing  from  2.50  to  3.00  of  silicon. 
For  results  of  higher  silicon,  see  next  paragraph. 


370  METALLURGY  OP  CAST  IRON. 

like  a  fishmonger  covered  with    shining-    fish    scales. 

When  metal  is  high  in  silicon,  its  surface  may  have 
a  smooth,  dead  appearance  devoid  of  life,  and  if 
the  surface  is  disturbed  with  a  rod  or  skimmer,  it  may 
act  a  great  deal  like  cream  upon  milk.  Were  it 
not  for  its  dull,  silvery,  quiet  appearance  and  spark- 
less  action,  it  might  often  be  taken  for  hard  iron. 
No.  i  iron,  whether  high  in  free  carbon  or  silicon, 
when  running  from  the  cupola  into  a  ladle  or  from 
the  furnace  to  the  pig  beds,  throws  off  very  few 
sparks,  and  those  that  do  fly  are  chiefly  caused  by  vi- 
bration of  the  metal  from  the  running  or  spluttering 
of  the  stream,  and  fall  as  ordinary  sparks,  very  differ- 
ent from  those  which  come  from  harder  or  lower 
grades  of  melted  iron. 

Irons  low  in  silicon  and  high  in  sulphur,  from  No.  7 
to  No.  10,  which  can  be  termed  hard  iron  and  also  can 
be  strong  and  weak,  have  peculiarities  very  pro- 
nounced to  distinguish  them  from  soft  grades  or  No.  i 
irons.  In  the  ladle,  such  irons  will,  when  "hot," 
show  a  smooth,  bright  appearance,  with  hardly  a  break 
on  the  surface,  and  as  the  mass  becomes  cool  or  "dulls 
down,"  it  presents  a  dull,  hazy,  plastic  appearance, 
which,  if  disturbed  by  a  skimmer  or  rod,  will  act  as  if 
it  were  covered  with  an  oxide  or  scum.  While  hot,  it 
will  often  boil  in  the  ladle  as  if  bubbles  of  gas  were 
escaping  from  below.  It  also  emits  many  sparks, 
which  is  the  chief  characteristic  phenomenon  of  hard 
iron  and  cannot  be  better  explained  than  in  the  lan- 
guage of  Tomlinson,  who  says : 

From  all  parts  of  the  fluid  surface  is  thrown  off  a  vast  number 
of  metallic  sparks,  from  the  absence  of  carbon,  which  renders  the 
metal  sensitive  to  the  oxidizing  influence  of  the  atmospheric  air. 


JUDGING    OF    AND    TESTING    MOLTEN    IRON.  371 

Small  spherules  of  iron  are  ejected  from  all  parts  of  the  surface 
to  the  height  of  five  or  six  feet,  and  sometimes  higher,  when  they 
inflame  and  separate  with  a  slight  hissing  noise  or  explosion  into 
a  great  many  particles  of  brilliant  fire,  forming  oxide  of  iron. 

The  blast  furnaceman  can  often  tell  very  closely  the 
' '  grade  ' '  an  iron  will  show  by  analysis  when  cold,  by 
its  appearance  when  fluid,  and  whatever  practical 
methods  a  founder  can  utilize  will,  at  some  time  or 
other,  prove  very  beneficial,  especially  in  "  air  fur- 
nace ' '  workings  and  long  ' '  heats  ' '  in  cupolas,  for  with 
the  latter  there  is  a  chance  given,  if  at  the  first 
tappings  iron  proves  itself  radically  wrong,  through 
any  errors  in  figuring  analyses,  or  in  charging  the 
iron,  etc.,  to  alter  the  charges  in  order  to  change  the 
' '  grade  ' '  of  the  metal  before  a  heat  is  finished. 


CHAPTER  LI. 

RESULTS  OF  VARIATION  IN  THE  FLUID- 
ITY   OF    METAL    AFFECTING 
PHYSICAL  TESTS. 

Variation  in  the  fluidity  of  molten  metal  is  a  fac- 
tor which  the  author  has  discovered  to  be  very  impor- 
tant to  note  in  considering  the  depth  of  an  iron's  chill, 
taken  by  means  of  a  test  bar  or  "  chill  block.".  It  is 
a  point  which  does  away  with  past  records  or  statistics 
which  have  been  compiled  by  some  from  deduc- 
tions taken  from  the  depth  of  a  chill,  by  the  pro- 
nounced manner  in  which  it  asserts  itself  in  giving 
evidence  of  being  affected  by  the  degree  of  fluidity  at 
which  a  test  bar  is  poured.  In  experiments  with  iron 
poured  * '  hot ' '  and  ' '  dull, ' '  the  author  has  made  the . 
thickness  of  chill  as  great  again  in  one  case  as  in  the 
other.  Take,  for  instance,  two  test  bars  and  pour  one 
hot  so  that  the  iron  will  run  up  in  the  fluidity  strips 
described  in  Chapter  LXVL,  page  509,  about  six  inches 
high,  and  then  cool  the  iron  so  as  it  will  only  run  up 
about  an  inch:  it  will  be  found  upon  breaking  the  bars 
to  test  the  chill  that  the  hot-poured  bar  will  have 
chilled  about  as  much  again  as  the  dull-poured  one. 
I  have  not  accepted  this  principle  as  a  fact  from  a  test 
or  two,  but  have  made  many  to  fully  assure  myself 
that  the  principle  is  correct. 


RESULTS  OF  VARIATION  IN  FLUIDITY  OF  METAL.        373 


The  Tables  seen  on  page  376  show  the  difference 
in  chill  by  reason  of  * '  hot ' '  and  ' '  dull ' '  poured  iron, 
in  test  bars  i^i  inch  diameter  cast  on  end.  It  will  be 
noticed  that  the  fluidity  of  the  hottest  poured  bar  in 
Table  82  was  but  four  inches,  and  the  dullest  one,  one 
inch,  a  difference  of  three  inches,  but  this  was  suffi- 
cient to  make  a  difference  in  the  chill  of  five-sixty- 
fourths  of  an  inch,  and  this  was  the  same  iron  poured 
out  of  the  same  ladle.  A  chemical  analysis  of  the 
iron  charged  in  the  cupola  and  that  obtained  in  the 

test  bars  is  also  given 
in  Table  82.  In  Fig. 
70,  K  shows  the  fract- 
ure of  the  hot-poured 
bar,  and  P  the  fracture 
of  the  dull-poured  one, 
from  which  a  good 
realization  can  be  re- 
ceived of  the  effects 
different  degrees  of  flu- 
idity can  cause  in  giv- 
ing different  depths  of 
chill  from  the  same  iron  poured  from  the  same 
ladle  and  which  is  forcibly  shown  by  the  Tables, 
page  376. 

In  the  Table  we  find  a  difference  of  .078  inch  in  the 
chill  of  the  two  ^-inch  bars  which  were  poured  out  of 
the  same  hand  ladle  holding  about  fifteen  pounds  of 
metal.  The  first  bar  was  poured  as  soon  as  the  metal 
was  carried  to  the  * '  floor, ' '  and  the  second  bar  three 
minutes  later.  Here  we  find  there  is  a  difference  in 
chill  of  .078,  due  to  difference  in  fluidity  of  metal,  or 
in  rough  figures  ^  inch,  as  seen  at  V  and  S,  Fig.  70. 


Dull  Iron 
Chill 


FIG.     70. 


374  METALLURGY    OK    CAST    IRON. 

I  state  the  time  between  the  pourings  to  give  an  idea 
of  how  long  the  metal  was  held. 

The  fluidity  strips  are  the  practical  guide  to  go  by. 
Of  what  use  is  time  in  regulating  or  asserting  the 
fluidity  of  irons  between  two  foundries,  or  one  heat 
from  another?  The  iron  in  no  two  foundries  is  of  the 
same  fluidity,  or  for  that  matter  the  same  foundry  will 
seldom  have  -two  days'  run  in  succession  alike,  and 
where  one  shop  could  only  hold  its  metal  for  five  min- 
utes, another  might  do  so  for  ten.  There  is  no  guide 
to  register  the  fluidity  of  molten  metal  better  than 
fluidity  strips  attached  to  test  bars,  as  advocated  by 
the  author  in  Chapter  LXVII.  For  scientific  re- 
search and  close  regulating  of  mixtures  by  physi- 
cal tests,  it  is  essential  for  fluidity  strips  to  be  at- 
tached to  test  bars,  where  one  desires  to  obtain  true 
knowledge  of  irons  or  mixtures.  I  have  shown  that 
degrees  in  fluidity  affect  the  depth  of  chill,  also  that  it 
is  incorrect  for  a  test  bar  to  pull  away  from  its  chill 
when  contracting,  as  seen  in  Chapter  LVI.  This  lat- 
ter evil  only  aggravates  more  the  one  caused  by 
different  degrees  in  fluidity,  as  both  elements  are 
effective  in  causing  erratic  depths  of  chill. 

I  could  have  shown  a  much  more  radical  difference 
in  the  chill  obtained  from  the  same  ladle  by  different 
degrees  of  fluidity,  and  would  here  say  that  in  one 
case  I  found  with  the  same  iron  in  pouring  two  J^-inch 
bars  that  the  dull-poured  one  had  a  chill  of  TV  inch, 
the  hot-poured  one  ^  inch,  a  difference  of  -f$  inch. 

For  any  that  desire  to  test  the  question  of  degrees 
of  fluidity  causing  different  thicknesses  in  chill,  in  (T2- 
inch  square  test  bars,  I  have  presented  the  plan  I  used 
in  my  experimenting  with  a  >^-inch  square  test  bar. 


RESULTS  OF  VARIATION  IN  FLUIDITY  OF  METAL.        375 

which  is  seen  below  at  Fig.  71.  In  using  this  device 
to  get  two  test  bars,  I  moulded  two  separate  patterns, 
in  a  flask  large  enough  to  admit  them  and  hav- 
ing four  inches  of  space  between  them,  so  that 
the  gas  or  heat  from  the  first  poured  one  could  not 
affect  the  other  bar.  The  flasks  were  leveled  so  as 
to  afford  like  conditions  for  the  running  of  the  met- 
al into  the  fluidity  strips.  For  chills  at  the  ends  of  the 
test  bars  I  used  pieces  of  ^4 -inch  square  wrought  iron 
rods,  cut  to  a  length  of  two  inches,  and  loosely  set 

them  against  the 
ends  of  the  pat- 
tern when  mould- 
ing. Should  any 

=L__J \xthick  one  desire  to  cast 

Sal  finch  square  Test  Bar  13  long  [          tWO      barS       at     the 

same  time  in  one 
flask,  they  would 

require,  of  course,  but  one  gate,  and  it  in  the  mid- 
dle, leaving  the  fluidity  strips  on  the  outside  of  each 
bar.  Fluidity-measuring  testing  tips,  cast  on  test  bars, 
are  an  entirely  new  departure  originated  by  the  author, 
and  found  by  him  to  be  of  much  value  when  very  close 
records  are  desired  for  comparisons  of  chill  records, 
etc.  The  plan  devised  for  using  fluidity  strips  with 
test  bars  cast  on  end  is  described  and  illustrated  in 
Figs.  121,  122,  pages  509  and  514. 


376 


METALLURGY    OP    CAST    IRON. 


TABLE    82. —  PHYSICAL   TEST    TAKEN   WITH    I>^-INCH    ROUND    BARS. 
Micrometer  Measurement. 


i 

. 

a 

.2 

jg 

.s 

IM 

O 

fc.2 

V 

• 

bo 

O      ' 

J.T  -. 

cu  rt 

J^  ^ 

** 

•; 

cd 

«i 

rt 

-*-»  j^ 

tJ-° 

tiS 

Q 

3 

a 

^J 

V 

Q  2s 

^4 

Bfi 

a"1  to 

"3 

'C 

a 

<J3 

P«O^4 

^ 

2-M 

OJ   C*,Q 

% 

£ 

5 

o 

u 

8 

ao 

J3 
O 

X""" 

2 

4* 

1 

?6 

:g» 

.120" 

.no" 

1,505 
1,500 

.172" 
.094" 

1.130" 
I.  I  17" 

1,501 

Common  Measurement. 


I 

2 

4" 
i" 

30 
16 

10-64" 
10-64" 

7-64" 
6-64" 

1,505 
1,500 

11-64" 
6-64" 

i  8-64" 
i  7-64" 

Analysis  of  Pigf  Iron  Charged. 

Analysis  of  Test  Bars. 

Silicon. 
1.46 

Sulphur. 

•039 

Silicon. 
1.26 

Sulphur. 
.072 

PHYSICAL   TEST    TAKEN    WITH    HALF-INCH    SQUARE   BARS. 


No.  of  Test. 

Fluidity. 

Deflection. 

Strength  in 
Ibs. 

Chill. 

i 

2 

iy," 

8" 

.190" 
.190" 

300 
290 

.048 
.080 

Analysis  of  Pig  Iron  Charged. 

Analysis  of  Test  Bars. 

Silicon. 

1.82 

Sulphur. 

•«35 

Silicon. 
1.67 

Sulphur. 
.056 

CHAPTER  LII. 

SPECIFIC    GRAVITY    OF   VERTICAL- 
POURED    CASTINGS. 

Below  is  given  an  extract  from  a  paper  by  the  au- 
thor, read  before  the  autumn  meeting  of  the  Iron  and 
Steel  Institute,  at  Birmingham,  England,  August  20- 
23,  1895: 

Some  authorities  have  asserted  that  a  test  bar  cast 
on  end,  if  placed  on  supports  equidistant  from  either 
end,  would  not  break  at  the  point  where  the  load  is 
applied,  but  at  a  point  an  inch  or  so  away  from  the 
point  of  pressure  toward  the  uppermost  cast  end  of  the 
bar.  In  a  long  experience  with  bars  cast  on  end,  the 
author  has  failed  to  find  any  such  condition.  Indeed, 
he  has  not  found  any  difference  in  this  respect  with 
bars  that  were  cast  flat  or  on  end.  With  a  view  to 
thoroughly  investigating  the  matter,  he  conducted  the 
following  experiment,  and  obtained  the  information 
given  by  the  Builders'  Iron  Foundry  of  Providence, 
R.  I.,  cited,  and  shown  in  Table  84,  page  379.  These 
are  tests  which  the  author  first  presented  in  a  discus- 
sion on  testing  at  the  meeting  of  the  American  Society 
of  Mechanical  Engineers,  held  in  New  York  City  on 
December  3,  1894,  and  later  gave  them  in  a  paper  be- 
fore the  Iron  and  Steel  Institute.  In  the  first  test  of 
specific  gravity,  he  wished  to  call  attention  to  the  fact 
that  the  specimen  used  was  strictly  a  parallel  gate  test 


378  METALLURGY    OF    CAST    IRON. 

bar.  He  mentions  this  fact  for  the  reason  that  in  the 
discussion  above  cited,  one  member  of  the  American 
Society  took  the  position  that  the  specific  tests  on  page 

379  were   inadmissible  proofs  to  establish    any  prin- 
ciple, owing  to  the  bottom  end  of  the  gun  which  was 
cast  down  being  of  a  more  massive  nature  than  the  up- 
per end,  and  hence  there  was  good  reason  to  expect 
metal  to  be  less  dense  in  the  bottom  than  in  the  upper 
end  of  the  gun.     The  following  test  of  the  parallel 
gate  which  the  author  conducted  shows  the  fallacy  of 
the  idea  that  the  lower  end  of  vertical-poured  castings 
must  be  of  a  greater  specific  gravity  than  the  upper 
end.     In  the  experiment  which  the  author  conducted 
at  his  own  foundry,  he  took  a  "  gate  "6^  feet  long  and 
3  inches  in  diameter,  which  had  been  used  for  pouring 
an  iron  ingot  mould  casting,  and  took  a  test-piece  6 
inches  from  the  top,  and  another  5  feet  from  the  top. 
The  gate  was  practically  parallel,  so  that,  in  turning 
these  specimens  in  the  lathe,  the  same  amount  of  sur- 
face was  carefully  removed  from  each.     The   speci- 
mens were  machined  of  exact  size,  and  were  then  de- 
livered to  the  laboratory  of  the  Case  School  of  Applied 
Science,  of  Cleveland,  O. ,  to  be  weighed.     The  deter- 
minations ( Table  83  )  reported  by  Prof.   C.  H.  Ben- 
jamin were  as  follows: 

TABLE   83. 

Weight  of  top  end  of  gate  in  vacuum 1169.468  grammes. 

Weight  of  bottom  end  of  gate  in  vacuum 1167.239         " 

Volume  of  top  end  of  gate 165.722  cubic  centimetres. 

Volume  of  bottom  end  of  gate 165.768     "  " 

1169.468 

Density  of  top  end  of  gate = =  7.0568. 

165.722 
"67.239 

Density  of  bottom  end  of  gate = =  7.0414. 

165.768 
Difference=o.oi54  only.    The  plug  from  the  upper  end  is  the  denser. 


SPECIFIC   GRAVITY  OF  VERTICAL-POURED  CASTINGS.     379 


Table  84  presents  a  series  of  tests  on  the  specific 
gravity  of  vertical-poured  gun  castings. 

TABLE    84. — TESTS    OF    SPECIFIC   GRAVITY    OF    FIRST    AND    LAST    SIX 
MORTAR    CASTINGS. 


Number  of  Heat. 

Specific  gravity  of 
muzzle  or  lop  end 
of  gun. 

Specific  gravity  of 
breech  or  bottom 
end  of  gun. 

78                         

7.238 

7.2478 

7  24^6 

7  2447 

&C' 

7.256 

87                                        .  . 

7.2934 

7  2882 

88 

7  27** 

7.285 

89.           

7-335 

7  329 

7.3263 

7  3182 

186 

7.3325 

7.3252 

j87                     

7.^04 

7-345 

188  

7.3636 

7-3336 

189                   

7-349 

7.340 

190 

7-3345 

7.3267 

Total         

87.6903 

87  6524 

7  y>7s 

7.3043 

The  lower  test  disc  was  taken  about  1 1  feet  from  the 
top  of  the  casting  and  the  upper  test  2^  feet  from  its 
upper  end.  The  majority  of  the  tests  showed  the 
specific  gravity  of  the  muzzle  specimens  to  be  higher 
than  the  breech  specimens  and  also  to  be  harder  and 
of  higher  tensile  strength.  This  is  the  reverse  of 
what  many  would  expect.  Table  84  shows  the  average 
specific  gravity  of  all  the  casts  made  for  specific  gravity 
of  breech  and  muzzle  specimens  on  the  first  six  mortar 
castings  and  on  the  last  six  mortar  castings  made  by 
the  Builders'  Iron  Foundry,  from  whom  the  author 
received  these  tests,  and  wishes  here  to  tender  his 
thanks  for  the  kindness  rendered. 

The  tests  and  figures  in  Tables  83  and  84  indicate 
that  there  is  no  condition  which  will  cause  any  prac- 
tical difference  in  the  lower  and  upper  end  of  long 


380  METALLURGY    OF    CAST    IRON. 

vertically-poured  castings,  in  the  sense  which  has  been 
generally  accepted. 

In  considering  the  gun  and  gate  tests  of  specific 
gravity  in  connection  with  those  referring  to  the 
density  of  the  lower  side  of  flat-cast  test  bars  being 
greater  than  the  top  side,  discussed  in  Chapter  LXV., 
it  would  at  first  seem  as  if  the  results  were  contra- 
dictory as  far  as  they  relate  to  the  enunciation  of 
any  law  or  principle  governing  the  quality  of  specific 
gravity  in  vertical-poured  casting.  The  gate  and  gun 
tests  show  the  upper  end  to  have  the  greater  specific 
gravity,  and  that  of  flat  poured  test  bars  to  have  the 
greater  density  in  the  side  cast  downwards.  The 
latter  is  largely  due  to  the  bottom  portion  or  sur- 
face of  flat-cast  test  bars  being  most  affected  by 
the  chilling  qualities  of  the  sand  of  the  mould  when 
it  is  filled  with  molten  metal.  If  the  specific  grav- 
ity had  been  taken  from  the  bottom  surface  of  the 
gate  test  bar  and  gun  castings,  instead  of  a  few 
inches  in  height  from  their  bottom  end,  as  was  done, 
there  might  have  been  a  difference  found  in  favor  of 
the  lower  end  being  the  denser.  This  is,  however, 
doubtful,  as  the  gun  and  gate  specimens  had  such  a 
small  area  exposed  to  the  mould's  cooling  influence, 
compared  to  the  mass  of  metal  comprising  the  castings. 
On  the  other  hand,  with  test  bars  cast  flat,  the  reverse 
occurred,  and  this  is  due  to  the  fact  that  a  fair  per- 
centage of  the  metal  comprising  the  test  bars  is  dis- 
tributed over  a  large  area  of  mould  surface  and  is 
affected  by  the  cooling  qualities  of  damp  sand,  which 
is  an  unnatural  effect  that  cannot  be  charged  to  spe- 
cific gravity  proper. 

When  the  specific  gravities  of  long  vertical-poured 


SPECIFIC  GRAVITY  OF  VERTICAL-POURED  CASTINGS.     381 


castings  are  tested  a  few  inches  from  the  bottom  and 
a  few  inches  from  the  top,  the  reason  for  rinding  the 
upper  end  the  denser,  as  exhibited  by  the  tests  record- 
ed, the  author  defines  as  being  largely  due  to  the  law 
of  metal  expanding  at  the  moment  of  solidification. 
Expansion  tending  to  make  the  upper  end  of  castings 
as  dense  as  the  lower  may  be  better  understood  when 
it  is  stated  that  molten  metal  begins  to  solidify  at  the 
bottom  of  a  mould  and  rises  in  height  as  the  solidifica- 
tion continues.  The  effect  of  expansion  at  the  mo- 
ment of  solidification,  as  castings  "  freeze  "  from  the 
bottom  upwards,  has  a  crowding  action,  tending  to 
make  the  molecules  denser  as  solidification  increases, 
thereby  partly  neutralizing  the  effect  in  the  difference 
of  the  specific  gravity  naturally  expected  to  exist  while 
the  metal  is  in  a  fluid  state.  The  author  has  obtained 
the  following  Table  85  of  analyses  of  the  top  and  bot- 
tom piece  of  the  vertical-poured  parallel  gate  test  bar 
from  E.  D.  Estrada,  M.  E.,  of  Pittsburgh,  Pa. : 

TABLE   85. 


Carbon. 

Phosphorus. 

Manganese. 

Silicon. 

Sulphur. 

Top  piece  
Bottom  piece- 

3-72 
3-81 

0.091 
0.085 

0.31 
0-33 

1.32 
1.32 

0.046 
0.047 

These  results  show  that  practically  there  is  little 
difference  in  any  chemical  constituent  that  might  tend 
to  equalize  the  specific  gravity  of  the  two  ends  of  the 
vertical-poured  "parallel  gate  test  bar,  and  that  we  are 
left  to  accept  the  author's  theory  of  such  results  being 
due  to  the  principles  involved  in  the  rate  of  cooling 
and  by  expansion  at  the  moment  of  solidification. 


CHAPTER  LIII. 

EXPANSION  OF  IRON  AT  THE  MOMENT 
OF  SOLIDIFICATION. 

The  question  of  iron  expanding  at  the  moment  of 
solidification  was,  up  to  about  the  year  1897,  affirmed 
by  some  and  questioned  by  others.  It  remained  for 
Mr.  John  R.  Whitney,  of  Philadelphia,  Pa.,  to  first 
demonstrate  in  a  practical  way  that  iron  truly  ex- 
panded at  the  moment  of  solidification.  This  was 
fully  verified  by  the  author  in  experiments  which  he 
conducted  immediately  after  Mr.  Whitney  published 
his  results  in  the  National  Car  and  Locomotive  Builder 
of  May,  1889,  of  which  the  following  is  an  extract, 
and  by  later  experi- 
ments shown  on  \  \ 
pages  384,  387  and 
424: 

On  a  more  recent  occa- 
sion the  following  exper- 
iment was  made  with  an  ~  FIG< 
apparatus  more  carefully 

prepared,  as  shown,  Fig.  72.  A  pattern,  A,  4  feet  long,  3^  inches 
deep  and  2^  inches  wide,  was  moulded  in  open  sand;  one  end  of 
the  mould  being  closed  by  fire  brick  B,  and  the  other  end  by  a 
piece  of  gas  carbon  D,  which  was  suitably  connected  with  a  small 
battery  and  galvanometer.  The  fire  brick  B  rested  at  one  end 
against  a  block  of  iron  C,  weighing  about  half  a  ton.  The  gas 
carbon  block  D  was  carefully  secured  in  the  sand,,  so  that  the 


EXPANSION    OF    IRON,     ETC.  383 

weight  of  iron  in  the  mould  should  not  be  sufficient  to  move  it. 
The  stand  K,  bearing  an  arm  J,  on  which  the  pointer  I  was  deli- 
cately pivoted,  was  then  adjusted  so  that  the  needle  F  should 
press  against  the  gas  carbon  D,  and  the  pointer  stand  at  zero  on 
the  scale.  The  long  arm  of  the  pointer  was  24  inches,  and  the 
short  one  6  inches  long,  or  as  i  to  4.  The  scale  was  graduated 
to  1-16  inch. 

A,  casting ;  B,  fire  brick ;  C,  weight ;  D,  gas  carbon  block ;  K, 
stand;  I,  pointer;  J,  supporting  arm;  F,  adjusting  needle. 

The  mould  was  filled  with  very  fluid  hot  iron  in  17  secoudss 
and  then  the  following  results  were  carefully  noted: 

For  more  than  i  minute  after  the  mould  was  filled,  pointer 
stood  at  zero. 

At  i  minute  30  seconds  after  the  mould  was  filled  it  moved  1-16. 

At  i  minute  50  seconds  after  the  mould  was  filled  had  moved  y%. 

At  3  minutes  10  seconds  after  the  mould  was  filled  had  moved  %. 

At  5  minutes  20  seconds  after  wl:?  mould  was  filled  had  moved  ^. 

At  8  minutes  5  seconds  after  the  mould  was  filled  had  moved 
7- 1 6. 

At  ii  minutes  30  seconds  after  the  mould  was  filled  had  moved 
15-32. 

At  12  minutes  5  seconds  after  the  mould  was  filled  had  moved  y2. 

From  that  time  the  pointer  stood  perfectly  still  at  y2  inch  until 
25  minutes  15  seconds  aft^r  the  mould  was  filled,  when  the  gal- 
vanometer showed  that  contact  with  the  gas  carbon  was  broken 
and  contraction  had  begun. 

I  have  made  several  other  equally  convincing  experiments,  but 
the  length  of  this  article  forbids  that  they  should  be  repeated 
here. 

Long  before  these  experiments  were  instituted  the  fact  that 
iron  follows  essentially  the  same  law  as  water  in  solidifying  was 
well  known  and  published.  I  need  cite  only  two  authorities: 
Prof.  Edward  Turner,  in  his  "Elements  of  Chemistry,  "published 
in  Philadelphia  in  1835,  by  Desilver,  Thomas  &  Co.,  says,  page 
20:  "Water  is  not  the  only  liquid  which  expands  under  the  reduc- 
tion of  temperature,  as  the  same  effect  has  been  observed  in  a 
few  others  which  assume  a  highly  crystalline  structure  in  becom- 
ing solid ;  fused  iron,  antimony,  zinc  and  bismuth  are  examples 
of  it."  Prof.  Thomas  Graham,  also,  in  his  "  Elements  of  Chem- 


384 


METALLURGY    OF    CAST    IRON. 


istry,"  published  in  Philadelphia  in  1843,  by  Lee  &  Blanchard, 
says,  page  385:  "  Iron  expands  in  becoming  solid,  and  therefore 
takes  the  impression  of  a  mould  with  exactness." 

As  the  observation  of  this  law  was  the  basis  upon  which 
my  experiments  leading  to  the  successful  development  of  the 
contracting  chill  for  cast  iron  car  wheels  was  based,  I  am  per- 
suaded it  will  lead  to  many  other  practical  results  of  great  impor- 
tance. This  is  my  apology  for  trespassing  upon  your  space  and 
calling  special  attention  to  the  matter. 

The  illustration 
seen  in  Fig.  73  is 
one  the  author  dis- 
played  in  the 
A  merican  Machin- 
ist, November  i , 
1894,  to  prove  that 
the  practice  of 
casting-  bars  be- 
tween iron  yokes, 
etc.,  prevented 
free  action  of  the 
metal  in  expand- 
ing. 

A  one-half-inch 
square  test  bar, 
twelve  inches 
long,  was  used  for  an  illustration.  The  author  has  tried 
by  this  device  one-half-inch  test  bars  without '  *  gates, ' ' 
pouring  them  in  "open  sand  "  or  without  a  cope,  and 
cannot  say  he  found  much  difference  in  their  expansion. 
If  any  difference,  the  one  with  the  gate  showed  the 
more.  H  is  an  iron  block  fitting  tightly  against  the 
closed  end  of  the  flask.  B  is  an  iron  block  fitted 
loosely  into  a  hole  in  the  open  end  of  the  flask,  as 


Cope 


Nowe 


FIG.   73. 


EXPANSION    OF    IRON,     ETC.  385 

shown.  D  is  an  arm  of  which  there  are  two,  one  be- 
ing, attached  to  each  side  of  the  flask  through  which 
the  pin  A  is  inserted  to  give  a  fulcrum  for  the  indica- 
tor arm  E  to  revolve  on  as  the  one-half-inch  square 
bar  expands. 

The  length  of  the  lever  E  is  seventy-two  inches  at 
the  long  end  and  the  short  end  should  read  one  and 
one-quarter  inches  instead  of  two  inches,  as  shown. 
The  dotted  line  of  the  indicator  shows  what  the  arm 
moves  at  the  time  of  expansion.  It  measures  about 
one-half  an  inch,  sometimes  going  over  this  mark, 
and  sometimes  a  little  under  it,  thus  disproving  the 
logic  that  small  bodies  or  test  bars  will  not  expand,  as 
claimed  by  some.  It  makes  no  difference  how  large 
or  small  a  body  is,  the  same  law  is  effective  in  all 
cases  of  metal  cooling  from  a  liquid  to  a  solid  body. 

By  referring  to  Chapters  LIV.  and  LV.,  pages  398 
and  424,  two  other  devices  originated  by  the  author  for 
recording  expansion  can  also  be  seen.  These  devices 
present  expansion  tests  which  show  the  reason  for 
there  being  no  practical  difference  in  the  specific 
gravity  of  the  two  ends  of  vertical- poured  castings,  as 
can  be  seen  in  Chapter  LII.,page  381.  Then  again, 
by  referring  to  Chapter  LIV.,  page  392,  the  effects  of 
expansion  in  causing  shrink  holes  in  castings  are  fully 
outlined. 


CHAPTER  LIV. 

THE  EFFECT  OF  EXPANSION  ON  SHRINK- 
AGE  AND   CONTRACTION   IN 
IRON  CASTINGS.* 

The  fact  that  Iron  expands,  when  heated,  until  fusion 
takes  place,  and  that  molten  iron  occupies  more  space 
than  cold,  solid  iron  of  the  same  grade,  is  now  uni- 
versally admitted.  It  was  proved  by  the  extensive 
experiments  of  Mr.  Thomas  Wrightson,  reported  in 
the  first  volume  of  the  Journal  of  the  Iron  and  Steel 
Institute  ( 1890  and  1891 ),  and,  in  a  manner,  is  illus- 
trated in  heavy  founding  by  the  shrinkage  of  the  mol- 
ten metal,  which  must  be  ' '  fed ' '  in  order  to  obtain 
solid  castings. 

This  decrease  in  volume  requiring  ' '  feeding  ' '  while 
the  metal  is  still  liquid  I  call  * '  shrinkage ' '  (see  pages 
394  and  395),  applying  the  term  "  contraction  "  to  the 
decrease  in  volume  which  takes  place  after  solidifica- 
tion, while  the  iron  is  cooling  to  atmospheric  temper- 
ature. The  light-work  founder,  not  having  the  oppor- 
tunity to  make  heavy  castings,  in  which  shrinkage  can 
be  observed,  is  apt  to  confound  the  two ;  but  they  are 
in  fact  distinct,  and  are  separated  by  an  act  of  expan- 
sion, which  takes  place  at  the  moment  of  solidification. 

*(Contribution  by  the  author  to  the  Discussion  of  the  Physics  of 
Cast  Iron,  at  the  Pittsburgh  Meeting,  February,  1896.) 


EFFECT    OF    EXPANSION    ON    SHRINKAGE,     ETC.  387 

The  fact  of  this  expansion  was  first  practically  demon- 
strated by  Mr.  John  R.  Whitney,  of  Philadelphia,  Pa., 
whose  experiments  are  recorded  in  the  National  Car 
and  Locomotive  Builder  of  May,  1889,  and  cited  in 
Chapter  LIIL,  page  382. 

Experiments  carefully  made  by  the  writer  indicate 
that  there  is  a  constant  relation  between  this  expansion 
and  the  preceding  shrinkage  and  forcibly  demonstrate 
the  necessity  of  "feeding"  a  casting  to  make  its  inte- 
rior solid.  This  is  a  matter  with  which  all  makers  and 
users  of  castings  have  experienced  difficulty.  The 
founder  being  heretofore  unable  to  define  correctly  the 
principles  involving  the  urgent  necessity  of  "feeding," 
has  failed  to  impress  the  moulder  with  its  importance 
in  making  sound  castings.  Heavy-work  founders  and 
moulders  know  that  hard  grades  of  iron  shrink  much 
more  than  soft  grades,  a  fact  for  which  no  satisfactory 
explanation  has  heretofore  been  given. 

By  recent  expansion  experiments  I  have  discovered 
that  hard  grades  of  iron  expand  more  at  the  moment 
of  solidification  than  soft  ones.  Fig.  74,  page  389,  is 
a  diagram  recording  four  such  experiments. 

The  manner  in  which  the  automatic  records  were 
obtained  will  be  described  further  on.  It  is  sufficient 
to  say  at  present  that  the  scale  of  inches  in  the  dia- 
gram measures  the  length  of  travel  of  the  pencils  on 
the  long  recording-arms  of  the  apparatus  employed, 
not  the  actual  length  of  expansion.  The  end  of  the 
short  arm  of  each  lever,  following  actual  expansion, 
travels  -fa  inch  for  i  inch  traveled  by  the  pencil,  and 
the  length  of  the  test  bars  being  48  inches,  i  inch  of 
the  expansion  or  contraction  record  represents  an 
actual  expansion  or  contraction  of  3  in  1536,  or  0.195 


388  METALLURGY    OF    CAST    IRON. 

per  cent.  For  the  purposes  of  these  experiments,  how- 
ever, the  actual  expansion  or  contraction  was  not  re- 
quired. 

The  significance  of  these  diagrams  is  qualitative  and 
comparative ;  and  for  this  use  of  them  the  reading  of 
the  pencil-travel  in  inches  is  accurate,  the  apparatus 
and  operation  being  the  same  in  all  the  tests  recorded. 
With  this  explanation  I  return  to  Fig.  74,  In  each  of 
the  four  casts  shown,  two  test  bars,  i  x  i|^  inches  in 
section  and  4  feet  long,  were  cast  "open-sand"  side  by 
side  in  the  same  mould.  Tests  Nos.  i,  3,  5  and  7  were 
poured  from  the  respective  ladles  which  brought  about 
100  pounds  of  the  iron  direct  from  the  cupola.  These 
tests  comprised  the  softest  iron  of  each  cast  and  had 
the  least  expansion  and  contraction,  as  is  shown  by  the 
diagram.  For  tests  Nos.  2,  4,  6  and  8,  the  grade  of 
the  iron  was  changed,  by  means  of  pouring  about  half 
of  the  hundred  pounds  contained  in  the  ladle  coming 
direct  from  the  cupola  into  an  empty  ladle,  the  bottom 
of  which  was  covered  with  about  three-quarters  of  a 
pound  of  brimstone.  The  metal  in  the  ladle  having 
the  sulphur  was  then  agitated  with  a  half-inch  wrought 
iron  rod  until  fuming  ceased,  after  which  all  dross  was 
skimmed  from  the  surface,  when  each  ladle  was  poured 
into  its  respective  test-mould.  The  addition  of  sulphur 
hardened  the  iron  in  these  tests,  thereby  causing  the 
increased  expansion  and  contraction  shown  in  the 
diagram. 

In  Fig.  75,  page  390,  tests  Nos.  9  and  10  illustrate 
another  discovery  made  by  this  method  of  compara- 
tive tests,  namely,  that  where  free  expansion  is  pre- 
vented, a  greater  contraction  is  effected  in  that  part. 

Test  bar  No.    9  was  cast  between  iron  ends,  so  ar- 


EFFECT    OF    EXPANSION    ON    SHRINKAGE,     ETC. 


389 


ranged  that  the  power  of  expansion  was  not  sufficient 
to  extend  the  distance  between  them,  whereas  No.  10 
had  sand  ends  to  compose  the  mould,  which  gave  full 
freedom  for  expansion,  the  same  as  in  all  other  tests 
displayed  in  Figs.  74  and  75.  The  fact  that  hard 


EXPANSION  SIDE. 

2              1 

CONTRACTION  SIDE. 

1              2              8               45              6         "^ 

Inches. 

First        J  Silicon 
Cast         |    1.17 

Second    VSilicor 
Cast         /    0.97 

Third      j  silicon 
Cast        ]    0.94 

Fourth   J  Silicon 
Cast        )    1.68 

Test  No. 
t                           | 

Sulphur,  0.031  per  cent. 

Sulphur,  0.306  per  cent.                                               ,         ( 

3                           1 

Sulphur,  0.028  per  cent. 

} 

Sulphur,  0.275  per  cent.                                           ,          i 

Sulphur,  0.032  per  cent. 

~*    *&i      i 

Sulphur,  0.2C8  per  cent.                           .                            ( 

7                               1 

Sulphur,  0.025  per  cent. 

8          | 

[ 

Sulphur,  0.3G8  per  cent.                               .                      ( 

2             1 

123456             7  Inches. 
1  1  1  1  1  1  1 

FIG.    74.— DIAGRAM  FROM   AUTOMATIC   RECORDS   OF   EXPANSION   AND 
CONTRACTION,    VARIED     BY    ADDITIONS   OF    SULPHUR. 

grades  of  iron  expand  more  than  soft  ones,  and  the 
fact  that  retarding  expansion  gives  rise  to  a  greater 
contraction  than  where  free  expansion  is  permitted,  are 
important  as  suggesting  for  works  making  such  spe- 
cialties as  chilled  rolls,  car- wheels,  etc.,  in  which  heavy 


39° 


METALLURGY    OF    CAST    IRON. 


losses  are  often  experienced  through  chill-checks  and 
-cracks,  the  advisability  of  adopting  expanding  and  con- 
tracting "chills"  wherever  this  may  be  practicable. 
Tests  Nos.  n,  12,  13  and  14,  in  Fig.  75,  illustrate 
the  expansion  and  contraction  of  different  sizes  of  bars 
poured  in  pairs  from  the  same  iron.  These  tests  show 


EXPANSION  SIDE. 
2                1 

CONTRACTION  SIDE. 
1              2             3              4             5              6             ' 

'  Inches. 

'Fifth 
Cast 

Sixth 
Cast 

Seventh 
Cast 

J  Si.  1.10 
1  8.  0.051 

j  Si.  1.08 
]S.  O.OJK 

J  Si.  1.18 
|S.  0.01£ 

Test  No. 
9 

Size  of  Bar  l"x  l%"x  4' 

| 

Size  of  Bar  l"x  If^'x  4'                                ,                        1 

11                      1  - 

Size  of  Bar  l^"x  2"x  4' 

12                       I-     •• 

I 

Size  of  Bar  1  x  1%'x  4'                                                        ( 

13                   1    •• 

Size  of  Bar  2"x  SJ^'x  4'  . 

1 

Size  of  Bar  1  x  1%  x  4A                    .                                   [ 

t.  ?             J 

123456             7  Inches. 

FIG.    75.— DIAGRAM    FROM    AUTOMATIC    RECORDS    OF   EXPANSION   AND 

CONTRACTION,    VARIED    BY    CONFINING    EXPANSION   AND 

BY    USING   BARS   OF   DIFFERENT    SIZES. 

that  large  bars  expand  so  as  to  increase  their  interior 
space  more  than  small  ones,  thereby  calling  for  the 
greater  "feeding"  in  massive  castings.  These  tests 
indicate  also  that  light  bars  contract  more  than  heavy 
ones,  an  element  not  to  be  overlooked  in  proportion- 
ing casting  so  as  to  avoid  internal  strains  so  far  as 
practicable,  a  quality  also  seen  on  page  420. 


EFFECT  -OF    EXPANSION    ON    SHRINKAGE,     ETC.  39! 

The  "  open-sand  "  method  of  casting  test  bars  affords 
the  means  of  making  comparative  tests  under  varied 
conditions  and  gives  an  excellent  opportunity  to  ob- 
serve characteristic  phenomena  at  the  moment  of  solid- 
ification, etc.  In  casting  test  bars  of  hard  iron,  a 
pronounced  shrinkage  along  the  upper  surface  is  often 
noticed  during  the  period  of  expansion ;  and  often  be- 
fore expansion  is  over  there  may  be  seen  through 
shrink-holes  at  the  hottest  part  of  the  bar  (namely,  at 
the  point  where  it  was  poured,)  that  the  interior  is  still 
liquid,  showing  that  it  is  not  necessary  that  the  whole 
body  of  the  casting  shall  solidify  before  expansion 
takes  place.  In  this  phenomenon,  we  perceive  also 
the  simultaneous  action  in  the  casting  of  two  opposite 
tendencies,  shrinkage  going  on  in  some  parts,  while 
expansion  is  occurring  in  others. 

It  is  the  general  impression  among  moulders  and 
founders  that  the  hotter  the  iron  is  poured,  the  more 
it  will  shrink,  that  is,  the  more  the  casting  will  require 
to  be  "fed."  This  is  an  error  into  which  the  moulder 
has  fallen  by  reason  of  the  longer  time  occupied  in  the 
cooling  or  shrinkage  of  the  "hot "-poured  metal,  and 
consequently  the  longer  period  of  ' '  feeding. ' '  The 
total  addition  of  iron  required  in  the  "  feeding-heads  " 
is  no  greater  with  "hot"  than  with  "dull "-poured  iron, 
unless  the  "hot "-poured  metal  has  more  largely  pene- 
trated, fused  or  strained  the  walls  of  the  mould. 

Numerous  experiments  have  failed  to  show  me  any 
effect  produced  upon  the  total  expansion  by  changes  in 
the  temperature  of  the  metal  when  poured.  Such  an 
effect  would  not  be  naturally  expected,  since  the  ex- 
pansion begins  only  with  solidification,  and  the  tem- 
perature of  solidification,  it  is  reasonable  to  say,  is 


392  METALLURGY    OF    CAST    IRON. 

always  the  same  for  the  same  grade  of  iron,  under  the 
conditions  of  these  tests;  so  that,  however  "hot" 
iron  may  have  been  poured,  it  will  always  have  a  cer- 
tain temperature  when  it  begins  to  expand.  But  it  is, 
of  course,  clear  that  expansion  will  take  place  sooner 
in  a  "  dull  "-poured  bar  than  in  a  "hot"  one;  and 
again,  a  light  body  will  expand  more  quickly  than  a 
heavy  one,  as  I  have  proved  by  my  tests. 

The  length  of  the  period  of  expansion  varies  with  the 
size  of  the  casting.  The  more  massive  the  casting, 
the  longer  the  period  of  expansion.  In  the  bars 
shown  in  Figs.  74  and  75,  the  expansion  lasted  from 
one-half  to  one  minute  in  the  smallest  bars,  and,  in 
the  largest  bars,  from  three  to  five  minutes.  The  re- 
lation between  the  shrinkage  and  the  expansion  of 
solidification  may  now  be  indicated.  The  author's 
view  is  that  the  apparent  shrinkage  of  liquid  metal 
so  familiar  to  heavy  founders  is  not  due  chiefly  to  a 
change  in  the  specific  gravity  of  the  liquid  metal  as  it 
passes  to  a  solid  state,  but  largely  to  the  effect  of  the 
expansion  of  the  solidifying  parts  of  the  casting. 
That  is  to  say,  an  outer  shell  of  the  casting  being  first 
formed,  its  expansion  at  the  moment  of  solidification 
necessarily  enlarges  the  interior  space  to  be  occupied 
by  liquid  metal;  and  either  additional  liquid  metal 
must  be  applied  or  else  cavities  and  shrink-holes  will 
be  found  in  the  interior  of  medium  and  heavy  cast- 
ings, by  reason  of  the  progressive  accretion  of  the 
solidifying  metal  upon  the  parts  already  solidified.  Such 
cavities  would,  on  this  hypothesis,  be  likely  to  be  most 
abundant  in  the  portions  which  solidify  last ;  and  that 
this  is  in  fact  the  case,  is  often  proved  by  practice. 
Cavities  are  very  liable  to  occur  in  the  interior  of 


EFFECT    OF    EXPANSION    ON    SHRINKAGE,     ETC.  393 

massive  castings,  and  even  when  castings  are  properly 
proportioned  the  portion  a-round  the  "gates"  which 
convey  the  metal  to  the  mould  is  often  very  likely  to 
be  porous  or  to  exhibit  shrink-holes,  due  to  the  cir- 
cumstance that  the  metal  solidifies  last  at  these 
points,  and  to  the  attraction  of  solidifying  particles  to 
the  already  solid  mass.  This  hypothesis  explains  also 
the  fact  that,  in  heavy  castings,  poured  "  hot,"  shrink- 
age is  not  often  exhibited  in  the  ' '  feeding-heads  ' '  un- 
til long  after  the  pouring,  and  that  when  it  does  com- 
mence (which  is  not  before  some  expansion  has  taken 
place,  due  to  parts  solidifying,)  it  is  often  so  rapid  as 
to  require,  for  a  short  period,  constant  additions  of 
molten  metal. 

Expansion  at  the  moment  of  solidification  being 
thus  one  cause  of  shrink-holes  in  castings,  the  practice 
(not  uncommon  among  moulders)  of  placing  ' '  risers, ' ' 
not  much  larger  than  lead-pencils,  so  to  speak,  on 
massive  castings,  thinking  thereby  to  make  them  solid, 
is  to  be  discouraged  as  useless.  It  follows,  moreover, 
that  a  casting  should  be  * '  fed  ' '  until  expansion  is 
ended.  It  is  not  while  a  metal  looks  * '  hot ' '  or  fluid 
in  a  "  feeding-head  ' '  that  attention  is  specially  neces- 
sary to  secure  a  solid  interior ;  it  is  when  the  metal  is 
thickening  or  ' '  freezing  ' '  in  the  ' '  feeding-heads  ' ' 
that  the  greatest  attention  should  •  be  paid  to  the 
"  feeding."  It  is  a  general  practice  among  moulders, 
at  present,  to  let  their  "  feeding-heads  "  "  bung  up  " 
at  a  time  when  the  greatest  effort  should  be  made  to 
keep  them  open,  so  as  to  insure  a  solid  casting.  It  is 
at  this  time  that  expansion  is  taking  place,  to  enlarge 
the  surface  area,  and  consequently  the  interior  volume 
of  a  casting,  thereby  causing  the  hottest  or  most  fluid 


394  METALLURGY    OF    CAST    IRON. 

portion  of  the  casting  to  be  robbed  of  metal,  which 
must  be  supplied,  in  order  to  prevent  shrink-holes  at 
all  such  points. 

According  to  the  view  here  presented,  it  will  be  also 
easy  to  understand  that  the  resistance  offered  by  the 
mould  may  often  effect  the  expansion  and  shrinkage  as 
well  as  the  subsequent  contraction.  Whether  the 
power  of  expansion  is  as  great  as  that  of  water  in  be- 
coming frozen,  is,  as  far  as  I  know,  undetermined.  I 
do  know  that  by  casting  between  iron  yokes  or  flask- 
ends,  the  longitudinal  expansion  of  the  bar  may  be 
prevented,  as  is  seen  in  Test  No.  9,  Fig.  75,  In  such 
a  case,  of  course,  it  is  natural  to  suppose  that  the  ex- 
pansion must  be  in  some  other  direction,  and  it  may 
increase  to  a  smaller  degree  the  interior  space  neces- 
sary to  be  supplied  with  molten  metal  by  feeding. 
The  heat-conducting  capacity  of  the  mould,  as  deter- 
mining the  rate  of  solidification,  may  also  effect  the  ap- 
parent result.  Thus,  a  casting  made  in  an  "  iron 
chill ' '  mould  may  show  less  shrinkage  than  if  the  same 
iron  had  been  poured  into  a  sand  mould,  because,  in 
the  latter  case,  the  solidifying  iron  could  have  time 
and  opportunity,  by  reason  of  the  nature  of  the  mould, 
to  more  expand  it  outward,  thus  increasing  the  inte- 
rior space  to  be  supplied  with  molten  metal  as  already 
explained. 

To  return  to  the  fact  discovered  by  the  writer, 
that  hard  grades  of  iron  expand  in  solidifying  more 
than  soft  grades,  it  may  be  said  that  this  is  contrary, 
not  only  to  the  general  impressions,  but  also  to  the 
current  explanation  of  the  fact  of  expansion,  which 
would  ascribe  it  to  the  creation  of  graphitic  car- 
bon. If  this  were  the  controlling  cause,  we  should  ex- 


EFFECT    OF    EXPANSION    ON    SHRINKAGE,     ETC.  395 

pect  soft  irons,  which  exhibit  after  solidification 
more  graphite,  to  show  the  greater  expansion. 

The  formation  of  graphite  is  confessedly  promoted 
by  silicon,  and  hindered  by  the  metalloids  which 
"  harden  "  the  iron.  When  these  metalloids  are  pres- 
ent in  such  proportions  as  to  overpower  the  effect  of 
the  silicon,  combined  carbon,  instead  of  graphite,  is 
produced  in  the  solidified  metal,  and  the  individual 
grains,  crystals,  or  structural  elements  of  the  cast 
iron  are  consequently  smaller  and  more  densely 
packed  in  hard  than  in  soft  grades  of  such  iron.  Ex- 
pansion (and,  perhaps,  also  contraction,)  would  be, 
therefore,  exhibited  by  a  larger  number  of  such  struct- 
ural elements  in  a  given  volume  of  metal,  to  be 
effected  by  changes  in  their  form  and  size.  This  may 
explain  the  greater  expansion  shown  by  the  hard 
grades  in  Tests  Nos.  2,  4,  6,  and  8  in  Fig.  74,  where 
the  largest  percentages  of  the  antagonistic  constitu- 
ents, silicon  and  sulphur,  are  presented.  (See  page  420.) 

But  any  theory  on  the  subject  may  be  premature. 
Far  more  important  at  this  time  is  the  fact  itself, 
which  affects  so  directly  our  foundry  practice.  I  at- 
tribute the  failure  to  detect  it  heretofore  to  the  circum- 
stance that  in  the  every-day  work  of  the  founder,  the 
expansion  of  solidification  does  not  force  itself  upon 
his  attention.  The  shrinkage  of  the  liquid  mass,  re- 
quiring '  *  feeding, ' '  is  obvious  enough ;  and  so  is  the 
final  contraction  of  the  solid  mass,  for  which  allow- 
ance has  to  be  made  in  the  pattern.  But  the  interven- 
ing expansion,  not  being  marked  b)r  the  final  contrac- 
tion, has  been  overlooked.  * 

I  may  here  observe  that  the  tests  illustrated  in  Fig. 
74  refute  the  opinion  heretofore  advanced,  that  the 

*The  subject  of  shrinkage  is  continued  at  the  close  of  this 
chapter  on  pages  404  to  414. 


396  METALLURGY    OF    CAST    IRON* 

silicon  contents  of  an  iron  can  be  defined  from  the 
final  contraction  of  a  casting  or  test  bar.  In  all  the 
bars  of  each  cast  in  Fig-  74  the  silicon  percentage 
was  nearly  constant.  The  variation  in  contraction, 
therefore,  certainly  justifies  the  assertion  that  the 
amount  of  silicon  cannot  be  thus  determined.  In  fact, 
the  contraction  will  simply  indicate  the  "grade"  of 
an  iron,  and  no  more.  The  metalloids  producing  this 
* '  grade  ' '  can  only  be  determined  by  analysis. 

The  "  grade  "  of  a  cast  iron,  as  I  use  the  term,  is  a 
practical  name,  familiar  to  heavy  founders,  though 
perhaps  not  capable  of  precise  scientific  definition.  It 
is  characterized  by  the  degree  of  hardness,  and  inci- 
dentally by  accompanying  properties  of  contraction 
and  of  strength.  This  question  of  "  grade  "  is  further 
discussed  in  Chapter  XX. 

It  has  been  maintained  that  it  is  difficult  to  make 
cast  iron  absorb  sulphur  and  that  the  founder  has  no 
need  to  fear  sulphur  in  general  founding.  *  In  the  tests 
shown  in  Fig.  74,  the  amount  of  sulphur  in  the  iron 
was  easily  increased  by  the  method  described,  as 
is  proved  by  the  subsequent  analysis.  At  all  events, 
I  am  sure  that  up  to  0.3  per  cent,  sulphur  can  be 
easily  present  in  cast  iron  containing  about  2.00  per 
cent,  of  silicon,  which  is  a  percentage  of  silicon  often 
permissible  and  practicable  as  a  maximum  in  light 
castings,  where  the  sulphur  can  be  kept  below  0.06 
in  the  castings  produced.  As  o.  2  per  cent,  of  sulphur 
is  sufficient  to  injure  or  ruin  almost  any  casting  made 
for  other  purposes  than  sash-weights,  the  ability  of 
cast  iron  to  absorb  as  high  as  o.  3  per  cent,  of  sulphur 
forcibly  illustrates  the  great  reason  why  the  founder 
has  to  fear  sulphur  in  fuel,  high-sulphur  iron,  and  to 

*  This  was  advanced  by  reason  of  results  derived  from  J^-inch 
test  bars,  in  a  lengthy  paper  seen  in  Volume  XXIII.  of  the 
Transactions  of  the  American  Institute  of  Mining  Engineers. 


EFFECT    OF    EXPANSION    ON    SHRINKAGE,     ETC.  397 

avoid  any  method  in  melting,  favorable  to  the  absorp- 
tion of  sulphur  by  iron  in  cupola  or  "air  furnace" 
practice.  These  considerations  are  applicable  also  to 
the  making  of  iron  in  the  blast  furnace. 

The  apparatus  used  for  obtaining  the  expansion 
and  contraction  records,  shown  in  Figs.  74  and  75, 
is  shown  in  Figs.  76,  77,  78,  and  79.  It  was  designed 
by  the  author  after  much  study  of  the  conditions 
necessary  for  automatic  record  of  the  expansion  and 
contraction  of  test  bars,  and  also  for  the  highly  im- 
portant purpose  of  simultaneous  comparative  tests. 

The  figures  illustrating  this  apparatus  (which  is 
freely  offered  for  use  to  all  who  may  be  interested  in 
the  matter)  will  be  readily  understood,  with  the  aid 
of  the  following  explanation : 

In  Figs.  76  and  77  the  same  letters  indicate  the 
same  parts,  namely: — 

A,  stationary  or  sliding  recording  face-plate  board ; 
B,  float;  D,  float-receptacle;  E,  regulator,  giving 
constant  head  of  water;  F,  supporting  arm  for  the 
water-supply  vessel ;  H,  over-flow  pipe ;  K,  L  and  M, 
recording  arm  levers;  N,  lead-pencil  recorder;  O,  rub- 
ber-band lever-supporter;  R,  curve-recording  face- 
plate board;  S,  slide-guides  for  recording  curves;  T, 
revolving  sheave-wheel  guide  and  support ;  U,  fulcrum 
cross-bar ;  Y,  supporter  of  fulcrum  cross-bar. 

In  Fig.  78  the  parts  are  indicated  by  letters,  as  fol- 
lows: 

A,  counterbalance  clock-weight;  B,  bed-plate,  se- 
curing the  base  board;  I,  one-day  "Pirate"  alarm- 
clock;  R,  curve-recording  face-plate  board ;  S,  remova- 
ble casting-pin;  U,  fulcrum  cross-bar;  V,  clock  and 
recording  face-board  connecting-shaft. 


V.-—  N 


M- 


m 


FIG.    76. — AUTOMATIC   RECORDING   APPARATUS   FOR   EXPANSION 
AND     CONTRACTION. 


EFFECT    OF    EXPANSION    ON    SHRINKAGE,     ETC.  399 

In  Fig.  79  the  parts  are  indicated  by  letters  as  fol- 
lows: 

A,  expansion  and  contraction-end  equalizer;  B, 
spring-clasp;  D,  flow-off  recess;  E,  spring-clasp  iron; 
F,  lever-fulcrum  bearing;  H,  casting-pin  clasp-open- 
ing; K,  removable  casting-pin. 

The  levers  of  this  apparatus  are  so  delicately 
mounted  as  to  be  moved  by  a  breath.  As  already 
stated,  for  every  inch  travel  of  the  long  arm,  the 
short  arm,  moved  by  the  actual  expansion  or  contrac- 
tion, travels  three  thirty-seconds  of  an  inch  in  the 
straight  line.  The  diagrams,  Figs.  74  and  75,  pages 
389  and  390,  were  constructed  by  platting  the  sum  of  the 
readings  given  by  the  pencils  at  the  two  ends  of  the  ap- 
paratus in  straight  lines,  and  consequently  give  only  the 
total  longitudinal  expansion  and  contraction,  without 
indicating  rate  or  alternations.  But  the  apparatus  can 
be  employed,  with  the  aid  of  the  float  or  clock,  etc., 
shown  in  the  figures,  to  record  curves.  For  a  straight 
line  record,  the  face-plate,  A,  Figs.  76  and  77,  is  held 
stationary.  To  obtain  curves,  it  is  gradually  lowered 
at  any  desired  rate  by  means  of  the  float  B,  in  the 
receptacle,  D,  Fig.  77,  a  constant  head  of  water  being 
maintained  in  the  reservoir,  E,  by  a  supply  from  a 
suspended  vessel  at  F,  and  an  overflow-pipe,  H.  A 
specially  arranged  strong  spring  clock  might  be  used 
instead  of  the  float  B,  to  lower  this  face-board  uni- 
formly, so  as  to  effect  the  same  end,  and  with  either 
plan  introduce  into  the  results  the  element  of  time. 
Incidentally,  such  experiments  ought  to  settle  the 
question  whether  there  are,  as  has  been  declared,  two 
periods  of  expansion  in  cast,  iron  when  it  is  cooling, 
after  the  liquid  metal  has  "  frozen,"  or  solidified. 


R~" 


\ 


FIG.    77. — AUTOMATIC   RECORDING   APPARATUS    (SEEN    FROM    OPPOSITE    SIDE 
OF  FIG.  76),  WITH  ARRANGEMENT  FOR  RECORD   IN   CURVES.     Q 


EFFECT    OF    EXPANSION    ON    SHRINKAGE,    ETC.          401 


The  lever-arms,  K,  L  and  M,  Figs.  76  and  77,  are 
held  gently  against  the  face-plate  by  light  rubber  bands, 
secured  midway  in  their  lengths  at  O,  so  that  the  very 
soft  pencils  at  N  may  record  all  movements  of  these 
arms.  The  pencil-record  may  be  made  on  paper,  cov- 
ering the  face-plate,  as  indicated  in  the  figures,  or  on 
the  bare  face  of  the  recording-board. 

It  will  be  evident  that  the  records  of  the 
independent  levers  at  each  end  of  the  bar 
must  be  added  together,  in  order  to  deter- 
mine the  total  expansion  or  contraction. 
Thus,  in  the  case  of  test  No.  i,  Fig.  7  4,  the 


FIG.    78. — INDEPENDENT    DIAL    FOR    RECORDING   EXPANSION 
AND    CONTRACTION    IN    CURVES. 

automatic  record  of  the  apparatus  would  show  a 
travel  in  expansion  of  one-half  an  inch  at  each  end, 
or  one  inch  in  all,  followed  by  a  contraction  of  two 
and  one-half  inches  at  each  end,  or  five  inches  in  all, 
not  including  the  retracement  of  the  previous  expan- 
sion. In  other  words,  after  expansion  was  ended,  the 
bar  contracted  longitudinally  eighteen  thirty-seconds 
of  an  inch  (each  inch  of  the  pencil-line  representing 


FIG.  79. — TEST  BAR  PATTERN  AND  LEVERS  FOR  RECORDING  APPARATUS. 


EFFECT    OF    EXPANSION    ON    SHRINKAGE,     ETC.  403 

three  thirty-seconds  of  an  inch  of  the  short-arm  lever- 
movement,  i.  e. ,  of  actual  extension  of  the  bar) ;  and 
consequently,  the  test  bar,  48  inches  long  as  poured, 
was  elongated  in  solidification  to  48-^-  inches,  and  then 
contracted  in  cooling  to  47^-  inches,  its  final  length 
at  atmospheric  temperature. 

The  clock  shown  at  I,  Fig.  78,  with  its  face-plate, 
R}  can  be  set  independently,  with  a  single  recording- 
lever,  to  receive  on  the  revolving  face  expansion  and 
contraction  curves  from  one  end  of  the  bar  only,  or  it 
can  be  supported,  as  shown  in  Figs.  76  and  77,  so  as  to 
record  curves  in  connection  with  the  records  made 
on  the  stationary  or  sliding  face-board,  A. 

The  whole  apparatus  is  of  wood,  except  the  fulcrum 
bars,  U,  Figs.  76,  77,  and  78,  the  casting-pin,  S,  Fig. 
75,  and  the  pin-holding  plates,  E,  Fig.  76.  By  a 
study  of  these  levers  in  Fig.  79  it  will  be  seen  that  a 
little  pressure  on  the  spring  side  at  B  will  instantly 
release  the  casting-pin  seen  at  K.  The  y%"  casting- 
pins  seen  at  S,  Fig.  78,  and  in  position  at  K,  Fig.  79,  are 
made  tapering,  so  that  they  can  be  readily  moved 
from  a  test-bar  and  used  again.  They  cause  the  levers 
to  record  sensitively  any  movements  due  to  expansion 
or  contraction  after  the  bars  are  poured.  At  the  left 
of  Fig.  79  is  seen  the  form  of  pattern  used  for  mould- 
ing the  test  bars.  The  projection  at  A  is  cast  on,  as 
shown,  so  as  to  insure  equal  action  in  recording  the  ex- 
pansion and  contraction  at  each  end  of  the  bar.  At  D 
is  a  recess,  which  gives  guide  to  make  the  same  in 
the  mould,  so  that  in  pouring  the  bars  * '  open-sand, ' ' 
the  metal  will  "  flow  off  "  at  this  point  when  it  comes 
to  that  level,  and  thereby  insure  all  bars  being  cast 
closely  to  the  same  thickness. 


APPENDIX  TO  CHAPTER  LIV. 

A   few   illustrations  of  shrinkage   and  blow  holes 

which  the  author  gave,  with  other  subjects,  in  a 
lecture  before  the  students  of  Cornell  University, 
December  14,  1900,  and  published  in  the  Sibley  Jour- 
nal of  Mechanical  Engineering,  January  and  February, 
1901,  are  presented  here,  as  they  contain  illustrations 
that  are  important  to  be  treated  in  connection  with 
the  subject  of  expansion,  shrinkage,  etc. 

When  a  shrink  hole  or  holes  occur  in  a  casting  they 
will  always  be  found  in  the  part  or  parts  which  solidify 
last.  To  prevent  such  holes  in  castings,  we  must  pro- 
vide means  to  fill  the  void  space  with  metal.  It  is 
often  difficult  and  again  it  is  impractical  to  do  so.  The 
chances  for  such  holes  occurring  are  often  due  to  the 
design.  There  are  times  when,  if  the  constructing 
engineer  or  designer  thoroughly  understood  the  cause 
of  shrink  holes  and  their  remedy,  he  could  design  or 
proportion  his  castings  to  avoid  such  evils.  The  ques- 
tion might  be  asked,  how  is  a  person  to  know  which 
will  be  the  last  part  or  parts  of  a  casting  to  solidify,  or 
where  we  may  expect  the  shrink  holes?  Such  holes 
will  always  be  found  in  the  upper  cast  part  of  uniform 
solid  castings,  as  seen  at  E  in  sample  No.  18,  Fig.  80, 
and  in  the  body  of  heavy  sections  having  light  ones 
joining  them,  as  at  F,  sample  No.  19;  that  is,  if  in  both 
cases  such  bodies  are  not  fed  with  additional  metal  to 
feed  the  shrinkage.  Where  light  parts  join  heavy  ones 


APPENDIX  TO  CHAPTER  LIV. TREATS  SHRINKAGE.     405 

the  light  parts,  solidifying  first,  will  naturally  obtain 
all  the  metal  required  to  feed  their  shrinkage  from  the 
heavy  part.  For  this  reason  if  we  do  not,  in  turn, 
supply  the  heavier  part  with  additional  metal  we  may 
expect  some  excessive  cavities  or  shrink  holes  in  them, 
unless  we  have  reason  to  suspect  that  the  creation  of 


FIG.    80.  —  CASTINGS    SHOWING    TYPICAL    POSITIONS    OF     SHRINK    HOLES. 

graphite  to  enlarge  the  grains  of  iron  is  such  as  to 
compress  the  metal  in  such  a  manner  as  to  prevent  the 
existence  of  shrink  holes.  Then  again,  there  are  cases 
where  the  expansion  of  cores  on  the  interior  of  cast- 
ings, while  the  metal  is  in  a  molten  state,  will  compress 
the  metal  so  as  to  fill  up  any  cavities  that  might  be 
caused  in  a  natural  way. 

A  good  illustration  which  shows  how  light  parts  will 
often  draw  metal  from  heavy  ones  and  leave  cavities 


406 


METALLURGY    OF   CAST    IRON. 


in  the  latter,  is  a  section  of  a  locomotive  pump  casting 
made  some  years  ago  in  Cleveland,  Ohio,  and  causing 
such  trouble  that  it  went  the  rounds  of  several  foundries 
before  good  castings  were  obtained.  A  section  of  this 
casting  is  seen  in  Fig.  81.  It  will  seem  strange  to  many 
unfamiliar  with  founding  that  moulders  did  not  under- 


FEEDER 


< 
>> 

i 


SSSB&SB^S^Sft 


/ 

/ 

^N\N 
G^G 

.XXWC 

\                                       V 

k^NSNS^C^^ 

v\^^^\>^C^^Cs^^ 

L 

J^\^l 

L 

8IBLEV  JOURNAL. 

FIG.   8l. —  LOCOMOTIVE    PUMP   CYLINDER    SHOWING   POSITION  OF  SHRINK 

HOLES. 

stand  how  to  make  such  castings  sound,  but  if  any 
such  ever  come  to  have  experience  with  foundries  and 
moulders,  they  will  find  that  too  many  of  them  are 
ignorant  of  the  principles  underlying  the  art  of  found- 
ing. The  difficulty  with  the  pump  casting  lay  in  there 
being  cavities  found  at  about  G,  as  marked  in  Fig.  81, 
when  the  section  was  bored  out  to  form  a  valve  seat. 
These  pumps  were  cast  on  end  and  at  all  angles ;  many 
were  made  with  good  large  skimming  gates  to 
hold  back  the  dirt,  thinking  such  to  be  the  cause  of  the 
imperfection  found.  Besides  this,  they  went  so  far  as 
to  make  them  in  dry  sand,  but  all  of  no  avail.  Finally 


APPENDIX  TO  CHAPTER  LIV. TREATS  SHRINKAGE.     407 


the  castings  came  to  the  hands  of  a  moulder  who 
understood  the  cause  of  shrink  holes  and  could  tell  such 
cavities  from  blow  or  dirt  holes.  After  this  moulder 
had  made  one  mould  and  observed  the  proportion  of 
thicknesses  in  the  casting,  there  was  no  more  trouble. 
The  difficulty  had  lain  in  not  providing  means  to  con- 
vey hot  metal  «to  supply  the  shrinkage  of  the  heavy 
part.  This  was  done  by  attaching  a  feeder,  as  at  H, 
having  a  connection  with  the  casting,  as  at  J,  both 
bodies  of  which  were  so  much  larger  in  area  than  the 
section  of  the  casting  at  G  that  assurance  was  afforded 
that  the  metal  would  solidify  in  the  heaviest  section  of 
the  casting  at  G  before  it  would  do  so  in  the  feeders  H 
and  J,  thus  giving  a  head  of  molten  metal  which  could 
settle  down  from  the  feeder  to  make  a  solid  casting. 
Pouring  these  castings  on  end,  instead  of  on  their  flat, 
could  do  no  good,  as  the  metal  would  solidify  first  in 
the  thin  part  of  L  long  before  it  would  do  so  in  the 
heavy  section  of  G.  If  a  heavy  feeder  as  at  the  dotted 
line  M,  made  of  the  same 
proportions  as  J  and  H,  had 
been  carried  down  from  the 
top  of  the  up-ended  mould 
to  the  heavy  section,  sound 
castings  would  have  been 
produced,  but  otherwise 
they  were  as  well  made 
on  their  flat  as  on  their 
end. 

Another  illustration  of 
this  principle  of  feeding  is 
found  in  not  obtaining-  8I8LEY JOURNAt; 

°  FIG.   82. —  CYLINDER  SHOWING  POSI- 

sound  flanges,  as  at  N,  r  ig.          TION  OF  SHRINK  HOLES. 


408 


METALLURGY    OF    CAST    IRON. 


82,  with  cylinders  cast  on  end.  The  feeding  head  O, 
which  is  intended  to  supply  the  shrinkage  of  all  below 
it,  is  often  made  so  small  that  it  solidifies  before  the 
heavy  portion  at  P,  and  then  what  metal  settles  to 
supply  the  shrinkage  of  the  lower  body  of  the  casting 
P  comes  from  the  thicker  or  more  fluid  section  at  N, 
and  leaves  shrink  holes  at  that  point.  This  whole 
difficulty  could  be  stopped  by  making  the  feeding  head 
O  larger,  as  per  dotted  line  R,  as  then  this  would  be 
the  last  to  solidify,  and  when  the  feeding  head  O  was 
cut  off  to  give  a  finished  flange  a  solid  body  of  metal 
would  be  found  under  it,  providing  the  feeding  head 
O  had  been  fed  with  hot  iron  by  means  of  a  feeder  or 
heavy  riser  head  (not  shown)  placed  on  top  of  the 
feeding  head  O  as  is  the  common  practice. 

Blow  holes.  Having  treated  the  subject  of  shrink 
holes,  we  will  say  a  few  words  on  what  are  called  blow 
holes.  Such  holes  may  often  appear  to  some  as  shrink 

holes,  but  they  gen- 
erally differ  in  be- 
ing found  in  lighter 
parts  of  castings, 
than  where  shrink 
holes  are  liable  to 
be  found,  and  are 
generally  of  a 
smoother  charac- 
ter. Not  only  are 
blow  holes  found 
on  the  interior  but 
the  exterior  as  well ; 
in  either  place,  they 
FIG.  83.— CASTINGS  SHOWING  BLOW  HOLES,  are  caused  by  gases 


APPENDIX  TO  CHAPTER  LIV. TREATS  SHRINKAGE.    409 


that  were  not  carried  off  from  the  mould  through 
proper  channels  of  venting  the  sand,  or  oxides  and 
slag  in  the  metal  giving  off  gases  that,  in  an  effort 
to  escape  from  the  metal,  become  imprisoned  in 
a  casting,  as  seen  at  S,  sample  No.  22,  Fig.  83. 
This  is  caused  by  reason  of  the  metal  solidifying 
before  the  gases  could  rise  upward  to  find  relief 
through  the  cope  or  top  part  of  the  mould,  and  which, 
if  not  well  vented,  or  of  a  porous  and  fairly  dry  char- 
acter, will  then  often  hold  the  gases  from  going  further 
and  form  cavities  in  the  cope  side  of  castings,  such  as 
seen  at  T  in  sample  No.  23  of  the  same  figure. 

A  description  of 
some  special  tests  on 
shrinkage,  contrac- 
tion, specific  gravity, 
and  fusion  that  the 
author  made  and  pre- 
sented in  a  paper  to 
the  Western  Found- 
rymen's  Association 
at  Cincinnati,  1897, 
are  given  in  the  fol- 
lowing. Prior  to 
these  tests  we  did  not 
possess  any  informa- 
tion as  to  what  per-  FIG-  S^-SHRINKAGE  PATTERN  AND  TEST 

CASTING. 

centage  of  shrinkage  ," 

there  existed  in  iron  when  cooling  from  a  fluid  to  a 
solid  state.  Realizing  the  advisability  of  obtaining  such 
information,  the  author  devised  the  following  method 
of  testing  the  shrinkage  of  the  different  metals  shown 
in  Table  86,  page  411,  and  illustrated  by  Figs.  84  and  85. 


METALLURGY    OF    CAST    IRON. 


At  M,  Fig.  84,  is  seen  an  iron  pattern  from  which 
sand  or  chill  moulds  may  be  made.  At  A,  Fig.  85,  is  an 
iron  box  three  inches  square  by  eleven  inches  long,  in 


FIG.  85. 

which  the  pattern  M  has  been  moulded  to  make  a  dry 
sand  mould  and  is  filled  with  molten  metal.  The  cut 
shows  a  moulder  in  the  act  of  pouring  the  contents 


APPENDIX    TO    CHAPTER    LIV. SHRINKAGE,   ETC.      411 


of  the  mold  into  a  chill  or  all-iron  mould.  This  is  split 
in  halves,  as  will  be  noticed,  and  a  ring  clamp,  as  at 
B,  is  used  to  hold  it  firmly  together,  E  being  a  bottom 
block  for  the  chill  proper  to  rest  on,  and  D  a  funnel 
cap  placed  loosely  on  the  top  of  a  chill  to  insure  the 
stream  of  metal  being  guided  directly  into  the  chill 
mould  without  any  being  spilled.  Before  pouring  these 
moulds  they  are  tested  to  learn  if  their  cubic  contents 
for  holding  metal  are  exactly  alike,  by  means  of  filling 
one  with  fine  hour-glass  sand,  and  then  pouring  the 
same  into  the  other.  This  is  done  only  as  a  precau- 
tion to  make  sure  that  no  extra  thickness  of  blacking 
or  distortion  of  the  dry  sand  mold  has  occurred  in  any 
manner  while  making  it.  There  are  three  of  these 
dry  sand  moulds  made  for  each  cast  or  test  of  any  one 
grade  of  metal,  two  being  called  portable  and  one 
stationary.  The  plan  of  using  these  moulds  is  as  fol- 
lows: A  portable  mould  is  secured  in  the  ladle  shank 
and  the  small  cupola  (page  241)  tapped  to  fill  it  direct, 
and  it  is  then  quickly  poured  into  the  chill  mould  as 

TABLE    86.— SHRINKAGE   AND   CONTRACTION   OF   GRAY    AND 
CHILLED    IRONS. 


Heat  Nos. 

i 

2 

3 

4 

5 

6 

Character  of  metal 
tested. 

Ferro- 
silicon. 

Foundry 
iron. 

Bessemer 
iron. 

i5t  steel 
with 
gray  iron 

Charcoal 
iron. 

Charcoal 
iron. 

Silicon  

12.25 

1-75 

1.72 

1.61 

•75 

.70 

Sulphur  

.021 

.04 

•054 

•055 

•03 

•035 

Shrinkage  of 
chilled  iron 

3oz. 
240  gr. 

2  OZ. 

240  gr. 

2  OZ. 

180  gr. 

2  OZ. 

290  gr. 

6  oz. 

6oz. 

280  gr. 

Shrinkage  of 
gray  iron  

3oz. 

I  OZ. 

2iogr. 

I  OZ. 

140  gr. 

I  OZ. 

460  gr. 

2  OZ. 

120  gr. 

Contraction  of 
chilled  iron... 

.270" 

.262" 

.271" 

.322" 

.446" 

.460" 

Contraction  of 
gray  iron  

.24" 

.205" 

.211" 

.227" 

.229" 

•235" 

412  METALLURGY    OF    CAST    IRON. 

above  described  and  seen  in  Fig.  85.  This  done,  the 
first  sand  mould  is  removed  from  its  ladle  shank  and 
another  set  in  to  replace  it.  This  in  turn  is  also  filled 
with  metal,  and  instead  of  pouring  this  into  a  chill  it 
is  poured  into  the  stationary  sand  mould,  after  which 
it  is  then  removed  and  placed  with  its  mate.  We 
now  have  two  moulds,  one  a  chill  and  the  other  a 
sand  mould,  that  will  have  a  sunken  space  at  the  neck 
K,  Fig.  84.  To  learn  the  amount  of  shrinkage  that 
has  taken  place,  the  shrunken  and  unfilled  spaces  at  the 
necks  of  the  chill  and  the  dry  sand  castings  are  now 
filled  with  molten  metal  and  separated  from  the  main 
casting,  views  of  which  pieces  are  seen  at  E  and  H, 
Fig.  84.  The  straight  portion  at  H  is  that  created  by 
the  shrinkage,  which  takes  place  as  the  metal  is  being 
poured,  and  the  portion  at  E,  which  is  irregular  in  out- 
line, is  that  created  by  the  shrinkage  of  the  molten 
metal  in  cooling  to  a  solid,  to  leave  a  cavity  in  the 
main  body  of  the  roll  as  seen  at  the  right  of  Fig.  63, 
page  338,  after  the  moulds  have  been  poured  and  are 
released  by  splitting  the  end  of  the  roll  at  K.  The 
piece  at  E  is  the  other  end  up  from  that  shown  before 
being  removed  from  the  roll  K.  A  little  study  of  the 
sections  E  and  H  will  show  that  their  total  weight  (by 
fine  apothecary  scales),  minus  any  thin  wafer  sheets  of 
iron  that  might  be  found  sticking  to  the  walls  of  the 
dry  sand  mould,  that  had  not  run  out  as  metal  to  test 
the  shrinkage,  would  be  the  shrinkage  of  that  iron 
under  the  conditions  in  which  it  had  been  poured. 

By  referring  to  Table  86,  page  411,  it  will  be  seen 
that  we  have,  in  castings  measuring  about  two  and  a 
quarter  inches  diameter  by  seven  inches  long  (the 
actual  form  and  size  being  seen  at  M,  Fig.  84),  weigh- 


TH£ 


™ 


APPENDIX  TO  CHAPTER  LIV.  -  SHRINKAGE 


ing  nearly  eight  pounds,  a  shrinkage  in  the  chilled 
iron  of  about  six  ounces,  and  in  the  gray  about  two 
ounces.  This  means  a  shrinkage  of  about  four  and  a 
half  pounds  per  hundred  for  all  chilled  iron,  and  nearly 
two  pounds  per  hundred  for  all  gray  iron.  In  larger 


FIG.   86. — CONTRACTION  TEST   WITH    CHILL  AND  SAND  MOLDS,   AND 
PATTERNS. 

figures,  for  example,  with  a  twenty-ton  casting,  Table 
86,  would  imply  a  shrinkage  of  about  1,800  pounds  for 
all  chilled  iron  were  it  possible  for  all  of  its  body  to  be 
as  thoroughly  chilled  as  is  the  section  of  rolls  seen  in 
Fig.  62,  page  337,  and  800  pounds  for  the  gray  iron  if 
the  total  body  of  the  casting  does  not  get  up  in 
graphite  any  higher  than  the  rolls  hold .  it,  as  seen  in 
Fig.  61,  page  333. 


414  METALLURGY    OF    CAST    IRON. 

It  is  to  be  remembered  that  the  tests  of  iron  shown 
in  Table  86  do  not  include  an  iron  as  soft  as  is  neces- 
sary for  stove  plate  or  very  light  castings,  and  because 
such  grades  of  iron  are  softer  than  any  shown  in  Table 
86  they  would  possess  less  shrinkage.  The  tests  exhib- 
ited by  Table  86  demonstrate  positively  that  metal  will 
shrink  and  cause  trouble  by  leaving  holes  in  the  in- 
terior of  castings,  and  also  that  the  greatest  shrinkage 
exists  in  the  harder  grades  of  iron. 

The  relation  that  contraction  maintains  to  shrink- 
age, with  the  same  metals  (see  page  386),  was  another 
point  which  the  author  thought  well  to  obtain  knowl- 
edge of  while  conducting  the  experiments  on  shrinkage. 
In  order  to  test  this  factor  the  author  devised  the  appli- 
ance seen  in  Fig.  86,  and  which  permitted  casting  bars 
seen  at  the  left  of  this  figure  in  a  sand  and  chill 
mould,  to  test,  together  with  other  qualities,  the  differ- 
ence in  contracting  that  would  be  caused  by  rapid  and 
slow  cooling  of  the  same  metal.  By  Table  86  we 
find  that  tests  Nos.  i  and  6  give  us  the  mean  of  .127 
greater  contraction  for  the  fast  cooled  bars  than  for 
the  slow  cooled  ones,  each  of  the  same  cross  section 
and  length,  patterns  for  which  are  seen  at  the  left  of 
Fig.  86.  The  greatest  difference  in  Table  86  is .  225  and 
the  smallest  .030.  It  is  to  be  remembered  that  the 
respective  tests  seen  in  Table  86  were  cast  in  their 
order  with  the  same  gate  and  hand  ladle  of  iron.  The 
cause  of  such  a  difference  in  the  contraction  of  two 
bars  is,  as  will  be  seen  by  Fig.  86  at  N,  that  one  is 
cast  in  a  chill  mold  and  the  other  in  sand,  P  being  the 
space  for  molding  the  sand  bar.  A  study  of  the  differ- 
ence in  contraction  which  the  rate  of  cooling  can  cause 
by  the  device  seen  at  Fig.  86  is  instructive  in  more 


APPENDIX  TO  CHAPTER  LIV. CONTRACTION,   ETC.     415 

ways  than  one.  Take  the  case  of  the  charcoal  iron 
heats  Nos.  5  and  6,  which  will  illustrate  the  great  diffi- 
culties the  makers  of  chill  rolls,  etc. ,  are  confronted  with. 
Here  we  find  that  the  chilled  part  of  the  casting  will  have 
as  much  again  contraction  as  the  body  of  the  casting 
that  is  not  chilled.  It  is  no  wonder  that  chill  roll 
makers  experience  much  trouble  with  the  checking 
and  cracking  of  the  surfaces  of  chill  rolls  due  to  the 
excessive  contraction  of  the  chilled  parts,  which  must 
leave  or  pull  away  from  the  chill  mold  supposed  to 
support  its  enclosed  body  of  liquid  metal  long  before 
it  has  solidified,  and,  which  by  reason  of  its  head  pres- 
sure incased  within  the  body  of  the  shell,  that  has 
contracted  from  its  chill  or  outer  support,  must  be 
heavily  strained  to  retain  its  enclosed  body  of  still 
fluid  metal.  We  can  see  by  the  chill  and  sand  contrac- 
tion tests,  herein  recorded,  how  a  very  slight  difference 
in  the  dampness  of  sands  or  nature  of  a  mould  can 
affect  the  contraction  of  castings,  or  test  bars,  and 
shows  us  the  necessity  of  having  uniform  conditions 
in  moulds  and  temper  of  sands  in  order  to  obtain  a 
true  comparative  record  of  contraction  tests.  More 
on  this  subject  is  found  on  pages  454,  467  and  511. 

Comparative  fusion  tests  by  immersion  were  con- 
ducted at  the  same  time  that  the  shrinkage  and  con- 
traction tests  were  made.  This  was  done  chiefly  to 
test  which  of  the  chilled  or  sand  cast  ends  of  one  bar 
would  melt  first  of  the  various  metals  used.  The  device 
the  author  designed  for  these  tests  is  shown  in  Figs. 
87  and  88,  the  former  figure  shows  a  three-quarter- 
inch  rod  in  the  hands  of  a  moulder  being  held  over  a 
ladle  that  holds  in  its  end  a  casting  made  in  the  mould 
seen  at  Fig.  88.  The  upper  half  S  was  all  green  sand 


4i6 


METALLURGY    OF    CAST    IRON. 


held  in  a  wooden  box,  and  the  lower  a  chill  or  iron 
mould  made  in  halves  and  held  together  By  a  ring  T, 
the  whole  resting  on  a  bottom  block  U  and  the  metal 
being  poured  in  at  Q.  Now  it  will  readily  be  seen 
that  a  casting  made  in  such  a  mould  would  have  one- 
half  wholly  chilled  or  body  hardened,  and  the  other  of 


FIG.   87. — LIQUID  BATH  COMPARATIVE  FUSION   TEST. 

a  softer  or  more  complete  gray  mixture,  which  if  held 
in  a  bath  of  molten  iron  or  steel  would  be  a  very  pro- 
nounced test  to  assist  in  showing  whether  hard  or  soft 
grades  etc.,  of  iron,  when  charged  into  a  cupola  or  air 


APPENDIX  TO  CHAPTER  LIV. TESTING  FUSION.        417 


Q 


furnace,  etc.,  as  such,  would  melt  the  faster.  The  cut 
at  Fig.  87  shows  the  exact  appearance  of  the  specimen 
as  it  was  taken  out  of  a  crane  ladle  bath  of  molten 
metal,  just  as  the  chill  end  V  was  about  to  disappear 
entirely,  and  which  we  have  found  in  all  cases  to  melt 
away  five  to  ten  minutes  faster  than  the  gray  end  X.  As 
the  question  of  encouraging  the  manufacture  of  chilled 
or  sandless  pig  by  the  blast  furnaceman,  which  this 
work  advocates,  is  an  important  one, 
the  author  would  advise  all  to  try  this 
experiment,  and  in  doing  so  many  will 
find  themselves  surprised  at  the  rapid- 
ity with  which  the  chill  or  body  hard- 
ened end  melts,  compared  to  the  gray 
or  soft  end  of  the  test  specimen.  In 
using  this  device,  some  judgment  will 
have  to  be  used  as  to  the  size  of  the 
test  roll  and  of  the  ladle  for  its 
immersion.  For  a  roll  of  two  to  three 
inches  diameter  a  one  thousand  pouna 

ladle  or  larger  will  be   necessary,  but 
FIG.  88.— COMPARA-  .  * 

TIVE  FUSION  TEST    rolls  about  one  inch  in  diameter  can 
MOLD.  often  be  meite(i  down  in  a  bull  ladle 

holding  two  to  three  hundred  pounds  of  iron,  before 
the  metal  would  get  too  dull.  These  rolls  are  well 
made,  about  twelve  inches  long,  and  are  secured  by 
the  end  of  the  rod  seen  curved  around  it  tightly  in 
the  center.  All  sand  and  scale  should  be  well  filed 
or  ground  off  from  the  sand  end  of  the  roll  so  as  to 
have  it  free  from  foreign  matter,  similar  as  in  the 
chilled  or  hardened  end,  to  make  conditions  alike  in 
each  end  as  far  as  possible.  Another  plan  for  testing 
fusion  is  given  on  pages  231  and  314. 


CHAPTER  LV. 

STRETCHING  CAST  IRON  AND  ELEMENTS 
INVOLVED  IN  ITS  CONTRACTION.* 

What  shall  I  allow  for  contraction?  is  a  question 
which  the  experienced  pattern-maker  will  generally 
ask  the  moulder  or  founder  before  any  patterns  of  im- 
portance are  begun.  It  is  true,  we  have  the  stereo- 
typed rule  of  allowing  one-eighth  of  an  inch  per  foot 
for  contraction,  and  many  pattern-makers  and  found- 
ers are  so  inexperienced  as  to  accept  such  a  rule  for 
the  contraction  of  every  form  and  thickness  of  a  pat- 
tern which  their  plant  may  be  called  on  to  make.  It 
is  possible  with  the  class  of  work  which  they  make 
that  such  a  practice  may  never  have  led  them  into 
difficulties,  and  hence  they  obtain  an  experience  which 
would  lead  them  to  believe  that  there  are  no  conditions 
calling  for  anything  else  than  the  making  of  all  pat- 
terns one-eighth  of  an  inch  per  foot  larger  in  every  di- 
rection than  the  castings  desired. 

Moulders  and  founders  of  broad  experience  in  gen- 
eral machinery  work  know  that  there  will  generally 
be  a  difference  in  the  contraction  in  any  two  forms 
that  differ  in  their  proportions,  even  when  poured 
with  the  same  iron.  Also  the  form  of  a  mould  and 

*  Read  by  the  author  at  the  meeting  of  the  Western  Foundry- 
men's  Association,  at  Chicago,  Nov.  20,  1895. 


STRETCHING    CAST    IRON,    ETC.  4*9 

the  manner  in  which  it  is  made  and  the  casting  is 
cooled,  have  much  to  do  with  the  size  of  the  casting, 
as  compared  with  the  pattern  from  which  it  was  made. 
It  is  not  the  intention  of  the  author  to  attempt  to  set 
forth  fixed  rules  for  the  contraction  of  castings  by 
the  classification  of  the  different  kinds  of  work,  as 
some  have  done,  for  this  is  not  practical,  but  more  to 
call  attention  to  the  principles  involved  and  assist  the 
engineer,  founder,  moulder  and  pattern-maker  to  best 
judge  what  contraction,  if  any,  should  be  allowed  for 
constructing  patterns,  to  meet  the  various  conditions 
in  moulding,  mixing  of  metals  and  cooling  of  castings. 
Not  only  has  the  experienced  heavy-work  founder 
found  a  great  difference  to  exist  in  the  contraction  of 
the  same  kind  of  iron  in  different  castings,  but  some 
will  agree  with  the  author  in  affirming  that  instead  of 
allowing  for  contraction,  the  reverse  conditions  occa- 
sionally prevail  and  are  elements  frequently  necessary 
to  be  considered  in  making  patterns.  It  is  nothing 
unusual  for  moulders  and  founders  engaged  in  heavy 
or  jobbing  machinery  to  find  their  castings  much 
larger  than  the  patterns  from  which  they  were  made, 
thus  disclosing  a  condition  in  founding  of  which  the 
light-work  founder  and  **  stove  plater  "  would  have  no 
opportunity  of  obtaining  any  knowledge.  Before  the 
author  discusses  the  qualities  involved  in  stretching 
cast  iron,  which  is  an  important  part  of  this  paper,  he 
will  consider  those  effecting  a  difference  in  thick  and 
thin  bodies  cast  under  the  same  conditions  or  in  the 
same  flask  with  the  same  iron  or  ' '  gates ' '  and  from 
which  observing  founders  have  learned  that  a  heavy 
casting  or  parts  will  contract  much  less  than  a  light 
one,  where  conditions  permit  of  free  contraction. 


420  METALLURGY    OF    CAST    IRON. 

An  experiment  which  the  author  conducted  to  dem- 
onstrate the  fact  just  cited  was  to  take  a  pattern  14 
feet  long  by  four  inches  by  nine  inches,  and  another 
exactly  the  same  length  but  only  one-half  inch  by  two 
inches,  and  cast  both  together  with  the  same  gates. 
Although  the  bars  were  of  the  same  iron,  a  difference 
of  seven-eighths  of  an  inch  existed  in  their  contrac- 
tion. The  thin  casting  contracted  one  and 'three-quar- 
ters of  an  inch,  whereas  the  thick  contracted  seven- 
eighths  of  an  inch.  Why  is  this?  is  a  natural  question, 
and  in  answer  the  author  would  offer  the  following 
hypothesis : 

The  carbon  held  in  fluid  iron,  authorities  claim  exists 
in  a  combined  form.  How  much  of  this  will  change  to 
graphite  when  the  castings  or  iron  has  solidified  and 
become  cold  enough  to  handle,  depends  first  upon  the 
time  of  cooling,  and  second,  the  percentage  of  sulphur, 
silicon,  manganese,  and  phosphorus,  which  exists  in 
the  iron.*  The  greater  the  silicon  up  to  nearly  four 
per  cent. ,  also  the  phosphorus  up  to  one  per  cent. ,  and 
the  lower  the  sulphur  and  manganese,  taking  account 
also  of  the  time  consumed  in  cooling,  the  higher  we 
will  find  the  graphitic  carbon.  The  greater  the  for- 
mation of  graphite,  the  larger  the  molecules  and 
grain  of  the  iron  ;  and  this  is  one  secret  of  thin 
castings  and  hard  iron  contracting  more  than  thick 
castings  and  soft  iron,  in  cases  where  all  conditions  in 
moulding,  cooling  and  freedom  for  contraction  are  sub- 
stantially alike.  For  other  .  qualities  effecting  this, 
see  pages  394  to  396. 

Two  castings  from  one  pattern,  of  the  same  iron,  can, 
by  cooling  one  more  quickly  than  the  other,  be  made  to 
show  considerable  difference  in  their  contraction,  ow- 

*  The  total  carbon  "is  also  to  be  included  when  thought  to  vary 
from  any  given  standard. 


STRETCHING    CAST    IRON,     ETC.  421 

ing  to  the  one  having  a  greater  time  than  the  other 
to  change  the  combined  carbon  to  graphite,  a  quali- 
ty the  author  noted  in  a  paper  before  the  Foundry- 
men's  Association  at  Philadelphia.  See  Chapter  LIX. , 
page  454.  This  Chapter  also  presents  analyses  of 
one-half  inch  and  one  inch  square,  as  well  as  one  and 
one-eighth  inch  round  test  bars  poured  from  the  same 
ladle  at  the  same  time,  showing  that  the  graphite  was 
much  less  in  the  one-half  inch  than  in  the  one  and 
one -eighth  inch  test  bars,  and  on  this  account  contrac- 
tion was  much  less  in  the  larger  than  the  smaller  bars. 

The  formation  of  graphite  may  be  compared  to  the 
raising  of  bread.  The  longer  time  given  for  the  yeast 
to  act,  the  greater  the  bulk  of  the  dough  obtained, 
caused  by  the  expansion  of  the  wheat's  molecules. 
This  is  similar  to  the  cooling  of  liquid  iron  to  a  solidi- 
fied cold  state.  The  longer  the  period  for  cooling,  the 
greater  the  expansion  of  the  molecules  and  grain  of 
the  iron,  which  is  defined  chemically  by  our  having 
higher  graphite  in  slow  than  in  fast  cooling  ;  this 
is  also  assisted  by  the  heaviest  parts  of  a  casting  or 
that  last  to  solidify  often  containing  silicon  to  have  its 
percentage  higher  than  will  be  found  in  the  lightest 
portion  or  those  first  to  solidify.  (Expansion  is  also 
a  quality  affecting  contraction  which  should  be  con- 
sidered in  connection  with  graphite.  For  effects  of 
expansion,  see  Chapter  LIV.) 

We  can  take  the  worst  kinds  of  scrap  iron,  and  by 
pouring  them  into  such  heavy  bodies,  as  anvil 
blocks,  for  example,  obtain  iron  that  presents  a  large, 
open-grained  fracture,  often  of  excellent  texture, 
proper  for  being  readily  machined;  whereas,  were 
the  same  iron  poured  into  a  casting  under  three  inches 


422  METALLURGY    OF    CAST    IRON. 

in  thickness,  it  would  be  "  white  "  and  hard  as  flint. 
In  the  former  case,  also,  it  would  show  much  less 
contraction  than  in  the  latter.  The  facts  go  to 
show  that  the  length  of  time  occupied  in  cooling  a  cast- 
ing, or  that  molten  metal  has  solidified,  may  often 
be  more  effective  in  causing  different  degrees  of  con- 
traction and  hardness  of  iron  in  a  casting  from  ordi- 
nary used  foundry  iron,  than  any  varying  percentages 
of  sulphur,  silicon,  etc. ,  which  exist  in  ordinary  found- 
ry iron.  Any  one  giving  due  consideration  to  the 
points  here  raised  will  be  led  to  concede  the  im- 
practicability of  formulating  set  rules  for  the  contrac- 
tion of  castings,  to  be  published  as  a  universal  guide 
to  desired  results  in  the  dimensions  of  castings ;  but 
by  a  study  of  the  phenomena  here  referred  to,  we  will 
be  in  a  fair  position  to  determine  what  allowance 
should  be  made  for  contraction,  etc.,  when  we  are  on 
the  ground  of  action.  It  is  to  be  understood  that  ref- 
erence is  not  made  to  the  difference  which  may  exist 
in  the  size  of  like  castings  from  soft  and  hard  iron,  or 
variations  due  to  the  hardness  of  ramming  and  head 
pressure  of  molten  metal  on  moulds,  etc.  We  are  main- 
ly dealing  with  the  elements  involved  in  the  question 
of  contraction,  as  affected  by  rapidity  of  cooling, 
stretching  of  iron,  and  variations  in  the  thickness  of 
metal,  etc.,  in  castings. 

Stretching  is  possible  and  due  to  influences  exerted 
by  conditions  in  casting,  cooling,  and  forms  of  patterns, 
which  overcome  or  retard  free  contraction.  It  can  make 
castings  larger  than  the  patterns  from  which  they  were 
made,  and  it  also  makes  it  possible  to  obtain  acceptable 
castings  which  could  not  be  secured  were  it  not  for  the 
fact  that  iron  can  be  stretched. 


STRETCHING    CAST    IRON,    ETC.  423 

The  author  will  now  describe  a  device  which  he  has 
designed  with  the  object  of  testing  and  proving  that 
cast  iron  stretches  as  well  as  expands.  While  the  cuts 
89  and  90,  pages  424  and  425,  will  explain  clearly  to 
some  the  exact  working  of  the  device,  I  will  describe 
it  in  detail  in  order  that  all  interested  can  criticise  and 
fully  understand  its  construction  and  working. 

A,  Fig.  90,  is  the  pattern  used.  The  shoulders  at 
B  and  C  are  for  the  purpose  of  providing  means  to 
stretch  the  bar  by  clamping  or  holding  one  end  to  a 
support  at  D,  Fig.  89,  which  has  a  recess  forming  a 
part  of  the  iron  frame  at  the  end  D  into  which  the 
projection  X  of  the  test  bar  pattern  A  is  inserted  when 
moulding  the  bar,  and  which,  when  cast  rigidly,  pre- 
vents the  test  bar  from  contracting  or  pulling  away 
from  this  end,  the  other  end  being  pulled  by  weights  as 
seen  at  E  where  one,  two  or  more  5o-pound  standard 
weights  are  suspended  over  the  roller  H.  There  are 
two  moulds  cast  side  by  side,  "  open  sand  ','  with  inde- 
pendent runners  R  and  T  from  the  same  ladle  of  iron 
as  quickly  as  they  can  be  poured.  The  only  differ- 
ence existing  in  these  two  moulds,  lies  in  one  being 
strained  by  the  weights,  while  the  other  is  free  from 
any  weight  or  restraint  to  prevent  contraction,  other 
than  the  restraint  of  the  mould's  sides,  and  this  affords 
the  most  favorable  arrangement  to  observe  and  record 
any  difference  which  may  exist  in  the  contraction, 
etc.,  of  free  and  restrained  bars.  Independent  point- 
ers are  attached  to  these  bars  by  means  of  levers  and 
show  their  readings  on  scales  behind  them. 

The  first  movement  of  the  pointer  to  be  noticed  is 
its  passing  to  'the  right  of  zero.  This  action  com- 
mences about  30  seconds  after  the  bars  are  cast  and 


METALLURGY    OF    CAST    IRON. 


FIG.    89. — WEST'S    STRETCHING    RECORDER. 


STRETCHING    CAST    IRON,     ETC.  425 

continues  for  about  90  seconds  for  a  total  travel  of  the 
pointer  of  about  one  and  one-half  degrees  on  the  arc 
shown  over  the  top  of  the  pointer  P.  This  is  caused  by 
the  expansion  of  the  metal  at  the  moment  of  solidifi- 
cation, a  quality,  by  the  way,  which  some  have  disputed. 
After  the  expansion  has  fully  recorded  its  influence, 
in  lengthening  the  bar,  the  pointer  P  stands  still  for 
about  two  minutes,  after  which  time  contraction  be- 
gins and  the  pointer  P  starts  to  move  back  to  the  left. 
The  weights  at  E  are  now  suspended,  and  it  will  be 
well  to  emphasize  the  fact  that  they  exert  no  influence 


'? 


LU 


•  3-4 "- 


01 


FIG.  00.  —  STRETCH  PATTERN. 


x 


to  suddenly  move  the  pointer  P  backward  to  zero. 
Five  minutes  after  the  contraction  commenced,  the 
restrained  bar's  pointer  will  have  moved  about  one 
degree  and  the  pointer  on  the  free  bar  two  and  one- 
half  degrees  to  the  left  of  their  starting  points.  About 
fifteen  minutes  after  the  bars  are  poured  the  restrained 
bar  will  have  moved  the  pointer  one  and  one-half  de- 
grees and  the  free  bar  three  and  one-half  degrees.  At 
30  minutes  after  the  pouring,  the  restrained  bar  will 
have  moved  the  pointer  three  degrees,  and  the  free 
bar  about  five  degrees,  showing  in  the  time  be- 


426  METALLURGY    OF    CAST    IRON. 

tween  15  and  30  minutes  after  the  pouring1  that  the 
restrained  bar  held  about  even  pace  with  the  free  bar. 

From  this  point  on,  the  restrained  bar  keeps  gaining 
on  the  free  bar,  until  the  end,  when  the  free  bar 
stands  about  one  and  one-half  degrees  ahead  of  the 
restrained  or  weighted  bar's  pointer,  thus  showing  we 
can  restrict  contraction  by  power  and  that  the  period 
of  the  greatest  stretching  of  cast  iron,  cooling  from  a 
solidified  state  to  the  temper  coldness  of  the  atmos- 
phere, wherever  there  is  any  restraint  upon  its  con- 
traction, is  that  ranging  from  1,600  degrees  F.  to 
1,200  degrees  F.,  or  in  color  from  a  light  to  a  dark 
cherry. 

One  reason  for  describing  the  above  tests  in  the 
manner  detailed  is  owing  to  the  fact  of  a  low  silicon 
mixture  being  used  with  but  two  5o-pound  weights 
suspended  to  retard  the  contraction.  Many  other  ex- 
periments were  made,  as  will  be  shown  further  on. 

In  closely  watching  the  movements  of  the  pointers 
of  the  restrained  and  free  bars  as  they  contract,  a 
wavering,  quick,  forward  (and  often  backward)  mo- 
tion, sometimes  as  far  as  one-half  degree,  will  be 
plainly  noticed  in  the  restrained  bar,  while  the  free 
bar  has  a  constant  steady  forward  movement.  The 
quick,  wavering  motion  is  occasioned  by  the  resistance 
to  free  contraction,  which  the  weights  offer  to  the  bar, 
and  occurs  when  the  contraction  occasionally  has  suffi- 
cient power  to  overcome  the  influence  of  the  weights 
to  stretch  out  the  cooling  iron.  The  fact  that  cast 
iron  can  be  stretched  is  also  often  exemplified  in 
heavy  foundry  work  in  the  cooling  of  castings,  exam- 
ples of  which  in  every-day  practice  the  writer  will  cite 
further  on. 


STRETCHING    CAST    IRON,     ETC.  427 

A  factor  not  to  be  lost  sight  oi  at  this  point  is 
the  positive  manner  in  which  the  device  here  de- 
scribed verifies  that  there  is  a  moment  of  expan- 
sion in  molten  iron  cooling  down  to  a  solidified  state. 
To  demonstrate  this  by  the  device  shown,  it  is  neces- 
sary to  cast  one  bar  between  fixed  iron  ends  which 
cannot  be  moved  apart  by  the  strain  of  the  expansion, 
and  another  bar  which  shall  have  the  end  at  the  pointer 
P  free  in  the  sand  to  record  any  expansion  which  may 
take  place. 

Any  one  experimenting  in  this  manner  will  find 
that  the  bar  left  free  to  expand  will  move  the  pointer 
to  the  right  of  zero  from  one  to  two  degrees,  while  the 
bar  cast  between  the  iron  ends  or  yoke  will  not  move 
the  pointer  until  it  starts  to  the  left,  thus  showing 
that  iron  will  expand  if  left  free  to  do  so. 

The  author  wishes  to  state  that  he  is  of  the  belief 
that  with  such  a  device  as  shown  founders  will  event- 
ually be  able  to  utilize  the  expansion  of  metal  to  de- 
note the  grade  of  hardness,  etc.,  in  the  short  period 
of  one  minute  after  the  molten  metal  has  been  poured. 
There  are  several  ways  in  which  such  a  quick  deter- 
mination of  the  grade,  etc. ,  of  metals  could  be  practi- 
cally applied  and  prove  of  some  value  to  the  metal- 
lurgical world. 

The  author  could  detail  all  the  tests  which  he  has 
made  to  show  the  movements  of  the  pointers  at  every 
few  moments,  but  as  what  he  has  given  is  in  a  practi- 
cal sense,  all  that  is  necessary  to  prove  the  theory  ad- 
vanced by  this  paper,  such  minute  details  have  been 
omitted.  Suffice  it  to  say  that  the  principles  in  ex- 
pansion, contraction  and  stretching  presented  are  not 
a  result  of  one  or  two  experiments,  but  of  a, 


METALLURGY    OF    CAST    IRON, 

large  number  of  tests,  and  that  with  a  weight  of  500 
pounds  suspended  at  E  and  an  iron  of  about  1.50  in 
silicon,  .050  sulphur,  he  has  made  a  difference  of  one- 
quarter  inch  in  the  final  contraction  of  the  free  and 
restrained  bars,  and  is  of  the  opinion  that  with  higher 
silicon,  or  a  softer  iron,  he  would  be  able  to  make  the 
final  stretching  of  the  restrained  bar  exceed  that  of 
the  free  one  over  'three-eighths  of  an  inch.  The  size 
of  pattern  A  is  one  inch  by  one  and  one-half  inch, 
and  three  feet  four  inches  long  over  all,  as  shown 
by  the  cut  at  A,  Fig.  90,  page  425. 

Returning  to  the  subject  of  stretching  cast  iron,  the 
author  will  cite  a  few  instances  in  every-day  heavy 
founding  that  will  further  assist  to  demonstrate  the 
existence  of  such  a  quality.  As  one  illustration  of  this 
fact,  I  refer  to  the  making  of  some  large  Martin  pump 
castings  which  I  made  in  the  year  1879  at  the  Cleve- 
land Rolling  Mill  Company's  foundry,  in  Cleveland. 

These  were  of  a  design  requiring  many  large  cores, 
and  when  the  patterns  were  made  the  usual  stereo- 
typed contraction  of  one-eighth  inch  per  foot  was  al- 
lowed for  the  castings.  I  had  made  about  four  of 
these  castings  when  I  was  one  day  called  upon  by 
the  manager  to  explain  to  him  what  I  had  done  to 
cause  the  castings  (cope  as  well  as  nowel  parts)  to  be 
larger  than  the  patterns,  which  had  caused  a  great 
loss  in  other  smaller  castings  that  would  have  to  be 
made  over  in  order  to  correspond  in  size  to  the  differ- 
ent parts  of  the  large  pump  casting.  The  investigation 
simply  resulted  in  showing  that  the  designer,  drafts- 
man and  pattern-maker  were  all  ignorant  of  the  quali- 
ties which  exist  in  cast  iron,  permitting  it  to  be  stretched 
when  cooling,  after  solidification  has  taken  place. 


STRETCHING    CAST    IRON,     ETC.  429 

It  is  natural  to  inquire  as  to  the  reason  for  the  iron 
being  stretched  to  such  a  large  degree  in  these  cast- 
ings. The  author's,  hypothesis  is  that  owing  to  the 
castings  being  filled  with  large  cores  containing  both 
slim  and  thick  cast  and  wrought  core  rods,  as  soon  as 
the  cores  became  heated  they  and  all  the  rods  ex- 
panded and,  by  outward  pressure  which  they  exerted, 
overcame  the  resistance  of  the  outer  body  of  the  green 
sand  mould ;  and  while  the  metal  was  in  a  fluid  state, 
instead  of  shrinking,  as  is  generally  the  case  with 
heavy  castings,  some  of  it  would  actually  flow  back 
and  run  out  over  the  flow-off  gates.  This  action  con- 
tinued until  solidification  took  place ;  then  stretching 
of  the  half  molten  or  solidified  iron  came  into  play, 
expanding  all  sides  of  the  green  sand  mould  until  the 
force  of  the  expanding  cores  and  their  rods  gave  way 
to  that  of  the  outer  mould's  body  of  metal,  and  the 
casting  attained  that  point  of  cooling,  as  shown  in  the 
experiments  illustrated  with  the  author's  device,  Fig. 
89,  in  which  it  had  cooled  sufficiently  to  overcome  the  in- 
fluence of  the  power  most  greatly  exerted  to  stretch 
the  iron,  thereby  exerting  an  expanding  power  at  a 
time  when  the  cooling  iron  was  most  susceptible  to 
stretching,  which,  of  course,  varies  according  to  the 
thickness  of  a  casting,  its  rate  of  cooling,  etc.,  to  ob- 
tain a  temperature  from  1,600  degrees  F.  down  to 
1,200  degrees  F. ,  as  cited  on  page  426,  in  the  stretch- 
ing tests  with  the  apparatus  above  described. 

The  case  of  the  pump  which  has  been  cited  exhibits 
a  form  of  power,  proper  to  be  classed  as  expansion 
and  compression  resistance  to  contraction.  We  still 
have  another  form,  which  I  will  call  heat  resistance, 
and  which  displays  its  power  to  stretch  iron  by  reason 


43<>  METALLURGY    OF    CAST    IRON. 

of  the  carbon  being  more  completely  transformed  to 
graphite  under  slow  cooling.  An  example  of  this  is 
an  experiment  which  was  made  by  a  New  York  City 
founder  some  years  ago. 

The  feat  achieved  by  the  founder  was  that  of  casting 
a  balance  wheel  of  about  18  inches  diameter,  having  a 
rim  about  two  inches  thick,  with  four  to  six  arms  only 
about  one-quarter  inch  thick.  The  wheel  was  on  ex- 
hibition for  some  time  and  the  wonder  of  founders  was 
how  it  held  together.  The  author  was  informed  that 
the  secret  lay  in  a  heating  device,  so  arranged  as  to 
keep  the  arms  at  a  high  temperature  and  to  preserve 
the  temperature  close  to  that  of  the  rim,  as  the  latter 
was  cooled  off.  The  author  would  say  that  the  feat 
was  not  achieved  wholly  by  reason  of  extended  heat, 
evolving  greater  graphite  carbon  in  the  arms.  The 
element  of  stretching  also  assisted  while  keeping  the 
arms  hot,  thus  permitting  the  pulling  power  of  the  rim 
to  extend  them. 

When  we  consider  the  difference  that  naturally  exists 
in  the  contraction  of  light  and  heavy  bodies,  so  clearly 
displayed  in  the  test  cited,  pages  390  and  420,  of  a  four 
by  nine  and  one-half  by  two  bar,  it  cannot  but  be  evi- 
dent that  had  the  above  wheel  been  left  to  cool  off 
naturally,  the  arms  would  have  pulled  away  from  the 
rim.  This  founder's  achievement  involves  a  lesson 
not  to  be  forgotten  by  any  interested  in  the  founding 
or  designing  of  machinery. 

The  ignorance  which  prevails  on  the  question  of 
contraction  is  very  often  astonishing.  It  is  only  the 
fact  that  cast  iron  will  stretch  that  saves  many  from 
having  their  ignorance  on  this  subject  exposed.  There 
are  many  castings  made  tliat  would  not  hold  to- 


STRETCHING    CAST    IRON,     ETC.  43! 

gather  were  it  not  for  the  stretching  property  of 
cast  iron.  In  this  case,  as  in  all  else  in  mechanics, 
there  is  a  limit  to  abuse,  and  it  is  not  infrequent 
that  we  find  this  limit  passed ;  but  when  it  is,  the  iron 
founder  is  almost  invariably  held  responsible  for  the 
results.  When  the  casting  cracks,  the  designer  is 
the  last  man  upon  whom  there  is  any  suspicion  of 
blame,  when  in  reality  he  often  is  the  one  at  fault. 

This  is  not  to  be  taken  as  relieving  the  founder  of 
all  responsibility  in  the  question  of  cracked  castings, 
etc.  When  the  principles  involved  in  the  stretching 
and  contraction  of  cast  iron  are  understood,  he  can 
often,  by  methods  of  cooling  and  permitting  freedom 
for  contraction,  do  much  to  partly  relieve  dispropor- 
tionate castings  of  internal  strains,  which,  if  they  do 
not  rupture  a  casting  before  it  leaves  the  founder's 
door,  may  often  do  so  after  it  has  gone  into  use.  It 
must  be  remembered  that  there  is  hardly  a  piece  of 
machinery  but  has  some  part  stretched,  or  held 
in  strain,  and  if  the  latter  is  the  case,  we  may  often 
fear  fracture  or  cracks,  eventually  causing  injury  to 
property  and  loss  of  life. 


CHAPTER  LVI. 

UTILITY  OF  CHILL  TESTS  AND  METHODS 
FOR  TESTING  HARDNESS. 

In  regard  to  the  general  utility  of  chill  tests,  some 
have  believed  that  if  a  founder  knew  what  an  iron  would 
"  chill  "  in  some  test  bars  or  block  chills,  he  should  be 
able  to  define  what  depth  of  chill  any  casting  would 
have,  no  other  qualities  being-  known  than  that  of  the 
iron  used  and  form  of  the  casting. 

There  are  numerous  elements  which  affect  the  depth 
of  chill  in  a  casting,  other  than  the  chilling  qualities 
of  the  iron  used,  which  make  it  impracticable  to  say 
just  what  the  depth  of  chill  in  a  casting  will  be, 
from  the  depth  of  chill  in  a  test  bar  or  block.  All  we 
can  do  with  a  test  bar  or  chill  block  is  to  get  a  relative 
knowledge  of  the  natural  chilling  qualities  of  an  iron. 
To  illustrate  this,  I  will  state  a  few  principles : 

First.  Any  casting  will  show  a  deeper  chilling  by 
remaining  in  contact  with  its  chill  until  all  the  metal 
in  the  casting  has  solidified  or  it  becomes  cold,  than  if 
the  union  of  the  casting  or  chill  were  broken  before  it 
had  occurred. 

Second.  A  hot-poured  iron  will  remain  longer  in 
contact  with  a  chill  than  a  dull-poured  iron,  for  as 
soon  as  the  molten  metal  has  solidified  it  commences 
to  contract,  and  hence  it  must  be  plain  to  any  one 
that  the  same  grade  of  iron,  if  pulled  away  more 


UTILITY    OF    CHILL    TESTS.  433 

quickly  from  a  chill  at  one  time  than  another,  will 
give  a  different  thickness  of  chill. 

Third.  The  least  difference  in  the  grade  of  an  iron 
causes  a  variation  in  its  contraction,  thereby  causing 
one  quality  of  iron  to  pull  away  from  a  side  chill  more 
than  another. 

Fourth.  The  thickness  of  chill  used  affects  the 
depth  of  the  chilling  in  the  casting,  up  to  the  limit  of 
the  chill  being  affected,  in  suddenly  extracting  heat  to 
counteract  the  carbon  at  the  surface  body  of  a  casting 
being  evolved  into  any  graphitic  carbon. 

Fifth.  The  thickness  of  a  casting  affects  the  depth 
of  a  chill. 

Sixth.  Degrees  of  fluidity  affect  the  chill.  A  hot- 
poured  iron  will  chill  deeper  than  a  dull  one.  See  page 

373- 

It  is  shown  by  the  above  that  certain  conditions  have 
an  effect  in  regulating  the  depth  of  a  chill  in  castings, 
and  that  it  is  impossible  for  any  one  to  tell  what  the 
exact  * '  chill ' '  will  be  in  a  casting  by  means  of  a  chill 
test ;  but  where  one  has  had  considerable  experience 
with  the  special  casting  and  takes  into  consideration  all 
the  elements  in  the  case,  he  can  closely  draw  his  own 
deductions  as  to  what  depth  of  chill  he  may  expect 
in  the  castings.  To  do  this  we  must  especially  consider 
the  thickness  of  our  casting  in  connection  with  the  iron 
used,  also  whether  the  casting  will  remain  in  con- 
tact with  its  chill  mould,  or  pull  away  from  it ;  also 
the  fluidity  of  the  metal  with  which  a  casting  is 
poured.  Further  information  on  chilling  is  found  on 
pages  258,  502  and  5 13. 


434  METALLURGY    OF    CAST    IRON. 

In  reference  to  testing  chilled  iron,  Mr.  Asa  W.  Whit- 
ney, in  a  paper  on  ' '  Chilled  Iron, ' '  before  the  Phila- 
delphia Foundrymen's  Association,  January  6,  1897, 
showed  that  the  transverse  strength,  as  well  as  the 
resilience  of  chilled  iron,  is  the  greatest  in  the  direction 
of  the  chill  crystals.  He  also  shows  that  '  *  tumbling  ' ' 
chilled  or  white  iron  is  not  as  effective  in  increasing 
the  strength  of  iron  as  is  the  case  with  medium  or  gray 
irons,  qualities  cited  on  pages  441  and  442. 

Reliable  methods  for  testing  hardness  of  iron  have 
long  been  needed.  It  is  often  as  important  to  test  the 
degree  or  character  of  hardness  in  castings  as  any 
other  physical  properties.  There  are  quite  a  number 
of  manufacturing  industries  of  the  character  like  chill 
roll  founders,  car  wheel  works,  crushing  machinery, 
die  and  brake  shoe  manufacturers,  that  could,  had 
they  but  a  good  reliable  hardness  test,  find  it  in  time 
to  be  as  important,  if  not  often  more  so,  than  any  ten- 
sile or  transverse  tests  they  could  use.  We  have  no 
physical  test  that  has  proven  more  unsatisfactory  than 
that  of  obtaining  the  hardness  of  iron.  However, 
improvements  are  being  made  as  shown  on  pages  435 
to  438  that  may  meet  many  requirements.  Many 
plans  have  been  used  to  ascertain  the  relative  hardness 
of  material.  One,  which  was  popular  for  a  time,  is 
said  to  have  been  proposed  by  Moh,  and  is  classed 
under  three  heads:  (i)  Any  material  which  could  be 
scratched  by  a  finger  nail,  (2)  that  scratched  by  a  knife 
blade,  (3)  and  that  affected  by  a  file.  After  the  above 
came  the  weighted  diamond  point,  followed  by  the 
punch  struck  with  a  given  weight.  The  diamond 
point  device  was  used  by  means  of  weights  sliding  on 
a  lever,  and  as  the  specimen  to  be  tested  was  moved 
the  weighted  diamond  would  trace ;  a  scratch  or 
leave  a  cut  the  character  of  which  recorded  the  hard- 


METHODS    FOR    TESTING    HARDNESS.  435 

ness  of  the  material.  An  apparatus  was  also  used 
having  an  obtuse-angled  hardened  point  which  would 
fall  from  a  height  upon  the  specimen  to  be  tested,  and 
according  to  the  size  of  the  indentation  made  the  hard- 
ness was  defined.  A  late  method  is  that  of  testing 
hardness  by  means  of  electricity,  in  which  a  current 
passes  through  the  specimen  to  be  tested  and  through 
other  standard  pieces.  The  current  necessary  to  pro- 
duce fusion  is  observed  and  compared  with  that  of  the 
normal  pieces  when  they  fuse. 

Up  to  about  1900  the  best  device  we  had  for 
testing  relative  degrees  in  the  hardness  of  metals  is 
that  of  Professor  Thomas  Turner,  who  stood  at  the 
head  of  professional  men  in  advancing  knowledge  on 
iron,  etc.  It  affords  the  author  much  pleasure  to  here 
present  a  cut  of  the  device,  accompanied  by  a  descrip- 
tion in  the  professor's  own  language: 

My  first  arrangement  is  as  follows,  Fig.  91 :  It  consists  of  a  bal- 
anced and  graduated  beam  of  gun  metal  A  working  on  steel  knife 
edges  B  and  counterposed  by  means  of  a  large  sliding  weight  F, 
the  final  adjustment  being  obtained  by  the  screw  G.  When 
balanced,  it  is  sensitive  to  o.oi  gramme  at  E,  though  such  delicacy 
is  not  probably  required.  The  knife  edges  rest  upon  planes  in 
the  support  C,  which  is  capable  of  rotating  on  a  steel  pivot  con- 
nected with  the  rod  D.  The  diamond  is  mounted  in  a  brass  tube, 
having  a  milled  head  which  is  fixed  by  means  of  a  screw  at  E. 
The  specimen  to  be  tested,  which  often  takes  the  form  shown,  J, 
is  supported  by  a  wooden  block  K.  The  weight  H  is  arranged 
so  that  each  division  on  the  graduated  scale  shall  correspond  to 
a  pressure  of  a  gramme  at  the  diamond  point.  Thus,  at  division 
12,  we  have  a  pressure  of  12  grammes  on  the  diamond.  Three 
extra  weights,  I,  are  used  when  necessary.  They  are  each  of 
the  same  weight  as  H.  Hence,  with  one  weight,  scale  division 
10  corresponds  to  10  grammes  on  the  diamond,  with  two  weights 
10  corresponds  to  20  grammes,  with  three  weights  to  30  grammes, 
and  with  four  weights  to  40  grammes,  the  other  scale  divisions 


43  6 


METALLURGY    OF    CAST    IRON. 


being  read  in  an  exactly  similar  manner.  It  will  be  noticed  that 
the  specimen  is  stationary  while  the  diamond  is  moved,  thus 
differing  from  the  scler- 
ometer  as  applied  to  min- 
erals ;  the  method  of  sup- 
porting the  beam  and  of 
applying  the  weight  is 
also  different.  In  ordi- 
nary experiments,  where 
considerable  weights  are 
applied,  the  diamond 
may  be  moved  by  the 
finger,  and  as  the  appa- 
ratus is  very  steady  in  its 
actions,  with  a  little  care 
this  gives  very  concord- 
ant results.  For  more  del- 
icate observations  with 
smaller  weights,  the  dia- 
mond may  be  drawn  by 
means  of  a  horizontal 
string  running  over  a 
small  pulley.  The  sur- 
face used  is  prepared 
roughly  in  the  ordinary 
way  by  chipping,  riling, 
etc.,  and  then  with  a 
smooth  file ;  it  is  finished 
with  emery  paper,  using 
at  last  the  finest  variety, 
or  flour  emery,  and  oil, 
according  to  the  material. 


A. 
B. 

C. 
D. 
E. 
F. 

C,. 


Beam. 

Knife-edge. 

Rotating  Support. 

Steel  Rod  and  Pivot 

Diamond. 

Sliding  Weight. 

Adjusting  Screw. 
H.    Sliding  Weight. 
I.    Extra  Weights. 
J.    Test  Piece. 
K.    Wooden  Support. 


FIG.    91. 


METHODS    FOR    TESTING    HARDNESS. 


437 


It  should  be  finished  all  one  way,  so  as  not  to  leave  small,  irregu- 
lar scratches,  and  should  be  as  smooth  and  bright  as  possible. 
As  a  rule,  an  experienced  workman  should  not  take  more  than 
half  an  hour  in  preparing  such  a  specimen,  although  occasionally 
a  hard  material  will  take  longer.  If  the  surface  tested  be  rough, 
the  results  are  erroneous,  being  generally  higher  than  with  a 
good  surface.  It  can,  however,  be  told  at  once  on  inspection 
whether  a  surface  is  suitable  for  the  purpose.  If  any  doubt  should 
exist,  another  smooth  face  must  be  prepared  and  the  experiment 
continued  until  uniform  results  are  obtained. 

The  following  Table  prepared  by  Professor  Turner 
clearly  presents  the  utility  of  his  device  and  illustrates 
the  thorough  manner  in  which  he  completed  his  work. 
It  has  been  thought  by  some  inexperienced  founders 
that  there  is  no  limit  to  silicon  softening  iron,  but  this 
is  strongly  refuted  by  the  following  Table  87  and  sus- 
tains the  author  in  statements  made  in  other  writings 
to  the  effect  that  silicon  can  harden  as  well  as  soften 
iron: 

TABLE   87. — INFLUENCE   OF   SILICON   ON   THE  HARDNESS   AND    TENACITY 
OF    CAST    IRON. 


No. 

Silicon  per  cent. 

Tensile  Strength. 

Hardness. 

i. 

0.19 

10.14  tons. 

72 

2. 

0-45 

12.31 

52 

3- 

0.96 

12.72 

42 

4- 

1.96 

15-70 

22 

i: 

2.51 
2.96 

14.62 
12.23 

22 
22 

7- 

3-92 

11.28 

27 

8. 

4-75 

10.  16 

32 

9- 

7-37 

5-34 

42 

10. 

9.80 

4-75 

57 

WORKING   QUALITIES, 
i.— Very  hard  indeed. 

2.— Very  hard,  though  not  so  hard  as  No.  i. 
3.— Hard,  though  softer  than  No.  2. 

4.— Good,  sound,  ordinary,  soft-cutting  iron,  of  excellent  quality. 
5.— Rather  harder  than  No.  4. 
6.— Like  No.  4. 

7. — Like  No.  6,  but  rather  harder. 

8. — Rather  harder  than  No.  7,  though  not  unusually  hard. 
9. — Still  harder,  cutting  very  like  No.  10. 
io.— Hard-cutting  iron,  though  still  softer  than  No.  i. 


43$  METALLURGY    OF    CAST    IRON. 

There  have  been  several  other  machines  designed  for 

testing  hardness  since  Professor  Turner  perfected  his 
machine.  One  is  a  design  by  Mr.  W.  J.  Keep,  being  an 
improvement  on  one  designed  by  the  late  Mr.  C.  A. 
Bauer,  M.  E.,  and  which  was  presented  at  the  New 
York  meeting  of  the  American  Society  of  Mechanical 
Engineers,  December,  1900,  and  also  described  in  the 
American  Machinist,  February  28,  1901.  Fig.  53  shows 
an  ordinary  drill  press  which  was  fitted  up  by  the  author 
to  test  the  hardness  of  metals,  and  which  worked  very 
satisfactorily  for  the  class  of  testing  it  was  intended 
for.  A  full  description  of  this  machine  is  given  on 
pages  234  and  238. 


CHAPTER  LVII. 

UTILITY    OF    TRANSVERSE,     CRUSHING, 
IMPACT   AND   SHOCK   TESTS. 

The  tests  called  for  in  our  engineering  and  other 
scientific  text  books  include  transverse,  tensile  and 
crushing  strength,  a  few  giving  impact.  Of  all  these, 
none  can  surpass  in  value  for  general  use  the  trans- 
verse test,  with  its  accompaniment  of  * '  deflection  ' ' 
for  foundry  practice,  simply  because  castings  are 
chiefly  subjected  to  such  strains.  The  utility  of  ten- 
sile tests  will  be  found  discussed  on  page  449.  The 
quality  of  cast  iron  to  withstand  crushing  loads  is 
also  one  often  of  much  importance  to  the  engineer 
and  founder.  The  values  found  by  the  author  from 
which  the  relation  between  crushing  and  tensile 
strength  may  be  deduced  lead  him  to  affirm  that 
the  elements  constituting  a  test  in  transverse,  de- 
flection and  chill  are,  for  general  purposes,  largely  a 
good  index  as  to  the  crushing  strength.  An  iron 
having  a  high  transverse  strength  combined  with 
small  deflection  should  prove  the  best  to  withstand 
crushing  loads. 

Impact  tests  on  the  side  of  bars  are  of  little  prac- 
tical value  in  assisting  to  determine  what  castings  can 
stand  in  shocks  or  blows.*  If  there  is  any  form  of 
tests  with  test  bars,  to  demonstrate  the  power  of  iron 
to  withstand  shocks  or  blows,  there  is  much  more 

*  This  has  reference  to  striking  test  bars  until  they  break,  and 
not  to  such  tests  as  are  outlined  on  the  next  two  pages. 


44°  METALLURGY    OF    CAST    IRON. 

practical  sense  exhibited  in  looking  to  high  transverse 
and  deflection  combined  with  a  low  contraction,  than 
to  impact  blows  on  the  side  of  a  test  bar.  A  prac- 
tical way  to  apply  an  impact  test  is  to  the  castings 
themselves.  The  car  wheel  men  teach  a  lesson  in 
this  respect.  Here  we  find  that  some  select  from 
a  large  stock  one  wheel  out  of  every  hundred,  and  if 
by  dropping  a  i4o-pound  weight  on  the  hubs  of  the 
sample  wheels  from  a  height  of  12  feet  the  sample 
wheels  stand  five  blows  each,  all  the  other  wheels  are 
then  accepted,  providing  they  have  stood  the  thermal 
test  described  on  page  443,  and  which  shows,  in  connec- 
tion with  the  above  impact  tests,  the  absurdity  of  think- 
ing to  be  guided  by  impact  blows  on  the  side  of  test  bars. 

The  power  of  castings  to  withstand  shocks  or  blows 
is  often  far  more  affected  by  their  proportion  or  design 
than  by  the  quality  of  iron  composing  them.  There 
is  altogether  too  much  indifference  exhibited  by  de- 
signers of  machinery  in  proportioning  castings  so  as  to 
have  the  least  possible  internal  contraction  strain  in 
them.  Some  designers  seem  to  ignore  wholly  the  fact 
that  a  light  body  will  contract  more  than  a  heavy  one. 
Many  castings  have  been  made,  the  iron  in  which 
would  test  all  right  as  far  as  test  bars  were  concerned, 
but  subjecting  them  to  shocks  or  blows,  would  imply 
that  the  iron  was  not  of  the  right  character.  This  again 
illustrates  the  impracticability  of  some  impact  tests  on 
bars  and  shows  that  a  weak,  high-contraction  iron  can' 
often  be  of  much  more  value  in  a  well-proportioned 
casting  than  the  reverse  kind  of  iron  in  an  ill-propor- 
tioned one. 

A.  E.  Outerbridge's  shock  tests  form  an  interesting 
study  in  this  connection.     In  these  tests,  Mr.  Outer- 


TRANSVERSE,  CRUSHING,  IMPACT  AND  SHOCK  TESTS.  441 

bridge  found  that  shocks  or  light  blows  delivered  on 
test  bars  increased  their  strength,  and  therefore  illus- 
trate the  benefits  to  be  derived  by  the  gradual  in- 
crease of  severity  in  shocks  to  strengthen  castings, 
such  as  guns  which  are  subjected  to  great  strains  from 
sudden  jars  or  blows  to  the  metal  comprising  their 
bodies.  They  also  show  wherein  many  castings  long 
in  use  can  have  their  durability  increased,  becoming 
really  better  than  new  castings. 

These  tests  were  made  by  means  of  twelve  compan- 
ion test  bars  that  had  been  moulded  in  one  flask  and 
cast  with  the  same  gate  and  ladle  of  iron.  Six  of 
these  test  bars  were  subjected  to  shocks  by  reason  of 
tumbling  in  a  "  tumbling  barrel, ' '  and  in  other 
cases  the  shocks  were  transmitted  to  the  test  bars  by 
means  of  tapping  them  on  their  ends  with  a  hand 
hammer.  The  six  bars  not  receiving  shocks  in  any 
manner  were  invariably  found  the  weakest.  The  bars 
receiving  the  shocks  were  shown  by  a  large  number  of 
tests  made  by  Mr.  Outerbridge  to  have  been  increased 
in  strength  from  ten  to  fifteen  per  cent,  and  the  larg- 
est gain,  in  a  few  instances,  was  found  to  be  about  19 
per  cent.  The  bars  tested  were  one  and  one-eighth 
inch  round,  and  also  square  bars  of  one  inch  section, 
both  fifteen  inches  long.  Mr.  Outerbridge  says  the 
crucial  test  was  in  subjecting  six  bars  to  3,000  taps 
each  with  a  hand  hammer  upon  one  end  only  of.  each 
bar.  The  tumbling  barrel  process  of  giving  shocks  to 
bars  continued  for  about  four  hours.  The  publication 
of  Mr.  Outerbridge 's  discoveries  by  trade  papers  .has 
led  many  founders  to  experiment  in  testing  his  deduc- 
tions, and  all  have  found  them  to  be  true,  some  even 
exceeding  the  strength  obtained  by  Mr.  Outerbridge. 


442  METALLURGY    OF    CAST    IRON. 

One  case  which  has  come  to  the  writer's  knowledge 
showed  a  gain  of  29  per  cent,  by  reason  of  tumbling 
test  bars.  For  results  with  chilled  bars,  see  page  434. 
Mr.  Outerbridge  was  led  to  demonstrate  that  shocks 
could  increase  the  strength  of  cast  iron  by  first  observ- 
ing that  chilled  car  wheels  rarely  cracked  in  ordinary 
service,  after  having  been  used  for  a  considerable 
length  of  time.  He  says  if  they  did  not  crack  when 
comparatively  new,  they  usually  lasted  until  worn  out 
or  condemned  for  other  causes.  Mr.  Outerbridge 
found  that,  up  to  the  point  of  the  shock  relieving  the 
internal  strains  by  permitting  the  individual  metallic 
particles  to  re-arrange  themselves  and  assume  a  new 
condition  of  molecular  equilibrium,  any  further  shock 
did  not  increase  the  strength.  He  does  not  say  this 
would  injure  it,  and,  in  speaking  of  a  few  practical  de- 
ductions for  universal  application  to  be  drawn  from 
his  tests  and  observation,  he  says :  '  *  Castings  such  as 
hammer  frames,  housings  for  rolls,  cast  iron  mortars 
or  guns,  which  are  to  be  subjected  to  severe  blows  or 
strains  in  actual  use,  should  never  be  tested  to  any- 
thing approaching  the  severity  of  intended  service.  * ' 
Mr.  Outerbridge 's  discovery  is  a  valuable  one,  and  can 
find  practical  application  in  many  ways,  especially  in 
showing  the  light-work  founder  that  "tumbling  "  cast- 
ings is  beneficial ;  but  that  it  is  best,  when  practical, 
where  there  are  any  fears  of  castings  being  broken,  to 
start  slowly  and  gradually  increase  the  speed  to  the 
limit  generally  practiced  when  "  tumbling.  "* 


*  The  paper  giving  all  the  tests,  etc. ,  was  originally  presented 
at  the  meeting  of  the  American  Institute  of  Mining  Engineers,  in 
Pittsburg,  Pa.,  February,  1896,  and  can  be  found  in  its  proceed- 
ings of  that  year. 


THERMAL  TESTS  FOR  CAR  WHEELS.  443 

METHODS  FOR  TESTING  CAR  WHEELS. 

The  Master  Car  Builders'  Association  requires  that 
wheels  should  run  for  a  period  of  forty-eight  months 
in  regular  service.  Before  they  are  removed  from  the 
foundry  they  are  subjected  to  a  thermal  and  drop  test, 
for  which  purpose  two  wheels  are  selected  by  an  in- 
spector from  every  lot  of  one  hundred.  We  cannot  bet- 
ter describe  the  methods  of  such  testing  than  by  an 
extract  of  Mr.  G.  W.  Beebe's  paper  in  which  he  cited 
the  C.  B.  &  Q.  Ry.  testing  specifications,  etc.,  before 
the  Western  Railway  Club,  and  published  in  the  Iron 
Trade  Review  of  October  2,  1900. 

«•  In  making  a  thermal  test,  the  test  wheel  (see  Fig. 
92)  must  be  laid  down  in  the  sand  and  a  channel  way 
i^  inches  wide  and  4  inches  deep  moulded  with  green 
sand  around  the  wheel.  The  clean  tread  of  the  wheel 
should  form  one  side  of  the  channelway  and  the  clear 
flange  the  bottom.  (It  will  be  noted  that  the  width  of 
the  channelway  is  equal  to  the  height  of  the  flange, 
namely  i^  inches.)  The  channelway  must  be  filled 
to  the  top  with  molten  cast  iron,  which  should  be 
poured  with  two  ladles  directly  into  the  channelway. 
The  molten  iron  must  be  taken  from  the  big  ladle 
directly  after  a  tap  for  pouring  the  wheels  has  been 
drawn  from  the  cupola.  The  channelway  must  be 
filled  with  the  molten  iron  in  no  greater  time  than  one 
minute  after  the  iron  has  been  taken  from  the  big  ladle. 
No  puddling  or  cooling  of  the  iron  will  be  allowed. 
If  the  molten  iron  boils  in  the  ladles  they  must  be 
refilled  until  all  indications  of  boiling  cease,  before  the 
channelway  is  filled.  The  time  when  the  pouring  ceases 
must  be  noted,  and  two  minutes  later  an  examination 


444 


METALLURGY    OF    CAST    IRON. 


made,  and  if  the  wheel  is  found  cracked  in  the  plates 
or  through  the  thread  the  wheels  represented  by  the 
test  wheel  will  be  rejected.  Wheels  that  are  wet  or 
have  been  exposed  to  the  frost  may  be  warmed  suffi- 
ciently to  dry  or  remove  frost  before  testing.  At  the 
option  of  the  manufacturer,  if  the  test  wheel  fails 
under  this  thermal  test,  a  second  wheel  showing 
the  next  lower  contraction  size  to  the  wheel  which 


N  CasHron 


gi  ^  -Green  Sand 


FIG.  92. — METHOD  OF  POURING   FOR  HEAT  TEST,  C.  B.  &  Q.  R.  R. 

failed,  and  cast  on  the  same  date  as  the  rejected  wheel, 
may  be  selected  by  the  inspector  ar.d  tested.  If  the 
second  wheel  stands  the  thermal  test,  all  wheels  of  the 
same,  and  all  lower  contraction  sizes,  may  be  accepted ; 
while  the  wheels  of  the  same  and  higher  contraction 
as  the  first  wheel  must  be  rejected." 

«•  The  contraction  allowed  on  a  cast  iron  wheel  is  ^ 
inch  —  %  inch  above  and  %  inch  below  the  mean  cir- 
cumference, divided  into  four  tape  sizes  of  }i  inch. 
The  tape  No.  i,  or  highest  contraction,  represents  the 
weaker  wheels,  conditions  being  normal.  The  inspec- 
tor being  aware  of  this,  almost  invariably  selects  tape 


THERMAL    TESTS,    ETC.,     FOR    CAR    WHEELS.  445 

No.  i,  or  highest  contraction  number,  for  the  test.  If 
tape  No.  i  fails  when  in  the  thermal  test,  reject  such, 
and  allow  the  inspector  to  select  one  of  tape  No.  2,  or 
next  lower  contraction  number;  and  if  the  second 
wheel  fails  reject  all  of  the  wheels  represented.  Pro- 
viding, however,  the  second  wheel  stands  the  thermal 
test,  it  seems  hardly  fair  to  the  manufacturer  to  con- 
demn the  second  and  lower  shrinkage  numbers,  the 
inspector  being  satisfied  by  the  test  on  the  second  tape 
sizes  that  they  are  sufficiently  strong  and  are  hard 
enough  to  give  the  wear.  An  inspector  should  make 
a  study  of  iron,  so  that  he  can  readily  designate  at  a 
glance  whether  the  first  wheel  failing  could  be  attrib- 
uted to  bad  iron  or  abnormal  conditions  in  the  pitting 
or  handling  of  the  rejected  wheel.  A  wheel  can  be 
made  of  a  hard  close  grain  iron  that  will  stand  the 
drop  test  or  concussion  in  service,  but  if  subjected  to 
a  severe  and  continued  brake  application  is  liable,  as 
boys  say,  "  to  go  up  in  smoke. ' '  A  gritty,  hard  chill 
will  not  make  the  mileage  that  a  tough  chilled  wheel 
will.  A  gritty  chill  will  shell  out  quicker  than  a  tough 
one,  because  it  will  not  stand  the  heat  that  is  caused  by 
severe  brake  application.  Good  white  iron  is  tough,  as 
well  as  being  hard  enough.  There  is  as  great  a  differ- 
ence in  the  quality  of  white  iron  as  there  is  in  gray 
iron ;  bad  white  iron  has  a  large  proportion  of  sulphur. 
I  believe  the  steel-tired  wheel  proves  that  the  tough- 
ness give  the  wear.  I  have  not  seen  or  heard  of  a 
steel-tired  wheel  shelling  out.  I  have  heard  some  rail- 
road men  say  that  when  they  can  cut  the  chill  of  a  wheel 
with  a  chisel,  the  wheel  will  not  make  good  mileage. 
If  this  is  the  case  the  steel  wheel  could  not  make  the 
mileage  that  is  claimed  for  it,  because  the  steel-tired 


446  METALLURGY    OF    CAST    IRON. 

wheel  is  turned  before  being  put  into  service,  and  it 
certainly  must  be  soft  in  order  that  it  can  be  turned. 
These  hard,  gritty  wheels  will  fail  in  the  thermal  test, 
or  by  severe  brake  application.  Regarding  the  depth 
of  chill,  it  should  not  exceed  y±  inch  in  the  throat,  or 
15-16  inch  in  the  center  of  the  tread.  The  minimum 
should  not  be  less  than  %  inch  in  the  throat,  or  fo  inch 
in  the  center  of  the  tread.  Assuming  that  we  have  the 
maximum  depth  of  chill — 15-16  inch  —  we  get  the 
blending  of  the  white  iron  through  the  entire  tread, 
and  begin  to  crowd  the  danger  line  and  gain  nothing, 
as  the  highly  chilled  wheel  will  shell  out  and  become 
capable  of  sliding  more  readily  than  a  medium  chilled 
wheel.  In  breaking  up  three  hundred  defective  wheels 
that  were  removed  on  account  of  shelled  spots,  95  per 
cent,  showed  a  high  chill. 

«« The  design  of  a  pattern  is  one  of  the  essential  factors 
in  the  manufacture  of  the  cast  wheel,  other  than  the 
thickness  of  flange,  shape  of  hub,  and  tread.  The 
designing  of  the  pattern  should  be  left  to  the  discre- 
tion of  the  manufacturer.  A  large  percentage  of 
wheels  that  fail  in  the  brackets  can  be  ascribed  to  a 
poorly  designed  pattern ;  too  light  brackets  will  crack 
because  they  cool  more  rapidly  than  the  plate  of  the 
wheel,  which  would  cause  a  strain  on  them ;  too  heavy 
a  bracket  will  throw  the  strain  on  the  plates,  causing 
the  plates  to  crack.  For  those  who  are  not  familiar 
with  the  drop  test  used  in  testing  wheels,  Fig.  93 
gives  an  illustration  of  the  Barr  drop,  and  Fig.  94  the 
M.  C.  B.  drop.  It  will  be  noted  that  the  hammer  of 
the  Barr  drop  strikes  the  single  plate  of  the  wheel  (see 
letter  A  on  Fig.  93).  The  hammer  of  the  M.  C.  B. 
drop  strikes  the  hub  of  the  wheel  (see  letter  A  on  Fig. 


DROP    TESTS,     ETC.,     FOR    CAR    WHEELS. 


447 


94).  A  wheel  rarely  fails  in  service  in  the  hub,  double 
plates,  or  at  the  intersection  of  the  plates  (see  letters 
A,  B,  and  C  on  Fig.  94).  If  a  crack  does  occur  at  these 
points  it  does  not  necessarily  cause  the  wheel  to  become 
dangerous.  If  a  crack  occurs  in  the  single  plate  (see 
letter  A  on  Fig.  93),  we  then  have  a  dangerous  wheel,, 
and  it  will  not  run  long  before  giving  way  entirely. 
It  will  also  be  noted  that  wheels  tested  under  the  M. 


FIG.   93. — BARR  DROP 
TESTING  MACHINE. 


FIG.   94. — M.   C.   B.   DROP 
TESTING  MACHINE. 


C.  B.  drop  are  placed  flange  downward  on  an  anvil 
block,  having  three  supports  for  the  flange  of  the  wheel 
•to  rest  upon.  The  hammer  strikes  the  central  part  or 
hub  and  the  whole  of  the  wheel  resists  the  concussion, 
while  the  wheels  tested  under  the  Barr  drop  are  placed 
flange  downward  on  a  flat  surface  anvil  block  and  the 
wheel  receives  the  concussion  at  one  point  only.  The 
Chicago,  Burlington  &  Quincy  specifications  require 
wheels  tested  under  the  Barr  drop  to  stand  fifty  blows 


448 


METALLURGY    OF    CAST    IRON. 


without  breaking  out  a  piece.  The  Pennsylvania  Rail- 
road specifications,  I  believe,  require  wheels  tested  to 
stand  twelve  blows  under  the  M.  C.  B.  drop  without 
breaking  out  a  piece.  It  would  seem  fair  to  assume 
that  the  Barr  drop  would  find  the  weak  or  dangerous 
part  of  the  wheel  more  readily  than  the  M.  C.  B.  drop. 
The  treatment  and  handling  of  the  hot  wheel  has 
nearly  as  much  to  do  with  the  strength  as  has  the 
material  used.  Cold  iron  will  produce  seams  in  the 
tread  and  internal  strains,  because  the  molten  iron  sets 
in  the  mould  as  fast  as  it  is  poured.  Hot  iron,  with 
slow  and  uneven  pouring,  produces  sweat  in  the  throat, 
uneven  chill,  and  internal  strains ;  delay  in  getting  the 
hot  wheel  into  the  pit  after  being  shaken  out  of  the 
mould  will  also  produce  strains  in  the  wheel  by  uneven 
contraction.  Wheels  should  be  poured  with  fairly  hot 
irons  and  fast.  The  limit  of  time  in  pouring  a  33 -inch 
wheel  should  not  exceed  twelve  seconds.  Table  88 
gives  the  analysis  of  a  number  of  wheels  tested  under 
the  Barr  drop,  and  in  the  thermal  test : ' ' 

TABLE   88. 


Wheels 
that  failed 
in  thermal 
test. 

Wheels 
that  stood 
thermal 
test. 

Wheels 
that  failed 
under  50 
blows,  Barr 
drop. 

Wheels 
that  stood 
50  blows 
and  over, 
Barr  drop. 

Max. 

Min. 

Max. 

Min. 

Max. 

Min. 

Max. 

Min. 

Total  carbon  ... 

3-91 

3^3 

3-90 

3.38 

3.87 

3-42 

3-93 

3-49 

Graphitic  carbon  

3-02 

2.92 

2.98 

2.71 

3-i9 

2.90 

3.02 

2.90 

Combined  carbon  

.89 

•71 

.92 

.67 

.68 

•52 

•91 

_^9_ 
.05 
•47 
.68 
.28 

Sulphur  

.090 

.042 

.10 

.080 

.080 

.020 

.070 

Manganese  

.60 

•49 

.58 

.48 

.62 

.40 

.72 

Silicon.  

.82 

•50 

•9i 

•50 

•97 

.67 

1.  10 

Phosphorus  

.48 

•39 

•52 

.26 

•58 

•30 

•53 

A  part  of  the  wheels  failing  under  these  tests  cannot  be  ascribed  to  the 
composition. 


CHAPTER  LVIII. 

ACHIEVING  UNIFORM  RECORDS,  AND 
UTILITY  OF  TENSILE  TESTS. 

Any  research  to  discover  uniformity  between  tensile 
and  transverse  tests,  up  to  about  1895,  shows  that  one 
plan  of  testing  gave  very  different  results  than  some 
others,  and  only  bewilders  instead  of  assuring  an  inves- 
tigator that  he  has  obtained  any  knowledge  of  the 
iron's  true  strength.  There  is  no  reason  why  the  same 
iron  should  show  such  erratic  records  as  have  been 
evinced  up  to  1895,  between  tensile  and  transverse 
tests,  that  can  be  charged  to  the  iron  proper. 

When  evils  due  to  casting  test  bars  flat  are  consid- 
ered as  proven  in  Chapter  LXV.,  one  great  cause 
for  the  wide  difference  recorded  in  the  past  is  clearly 
displayed.  How  is  it  possible  to  expect  other  than 
erratic  and  unreliable  records,  when  the  fact  of  a  flat- 
cast  one-inch-area  test  bar  being  200  to  400  pounds 
stronger  on  one  side  than  the  other  is  considered? 
Any  one  giving  thought  to  this  subject  cannot  but 
perceive  the  unreliable  records  which  casting  flat  must 
cause,  and  become  convinced  that  the  plan  of  casting 
on  end  far  surpasses  past  methods,  in  order  to  insure 
uniformity  between  tensile  and  transverse  or  either 
tests  taken  from  bars  cast  off  from  the  same  ladle. 

For  foundry  and  engineering  purposes  it  can  be  said 
that  tensile  tests  are  often  valuable  for  comparative 


45°  METALLURGY    OF    CAST    IRON. 

tests.  With  a  standard  length  of  a  bar  for  transverse 
strength  and  one  of  equal  area  for  tensile  testing  of 
the  round  form,  not  exceeding  i  ^  inches  diameter  and 
cast  by  the  system  advocated  by  the  author,  a  study 
on  comparisons  leads  him  to  say  that  transverse  and 
tensile  tests  will  be  found  to  bear  a  very  close  relation 
to  each  other,  and  prove  that  the  tensile  test  may,  for 
some  purposes,  be  of  as  much  benefit  for  a  comparative 
test  as  are  transverse  tests. 

When  test  bars  exceed  one  and  one-half  inch  diam 
eter  the  transverse  and  tensile  strength  tests  com- 
mence to  diverge  radically  in  opposite  directions,  the 
tensile  strength  decreasing  in  strength  per  square  inch 
while  the  transverse  increases,  a  point  more  fully 
explained  in  Chapter  LXX.,  page  571.  With  bars 
under  i^  inches  diameter  the  tensile  strength  will 
closely  average  ten  times  the  strength  of  transverse 
tests,  in  like  areas. 

One  difficulty  in  obtaining  tensile  strength  often 
lies  in  the  method  of  obtaining  them.  Some  machines 
can  take  such  a  rigid  grip  as  to  exert  a  strain  on  some 
portion  of  the  specimen,  instead  of  permitting  the  test 
bar  to  adjust  itself  centrally  so  as  to  insure  a  uniform 
pull  over  its  entire  breaking  area.  Cast  iron  requires 
different  treatment  to  insure  a  uniform  pull  than  steel 
or  wrought  iron,  but  with  the  use  of  specially  designed 
test  bars  permitting  a  good  area  for  gripping,  or 
having  shoulders  cast  on  each  end  with  holes  in  them 
at  cross  angles  to  each  end  whereby  pins  can  be  in- 
serted to  allow  a  specimen  to  adjust  itself  centrally 
to  its  load,  very  accurate  tests  may  be  obtained.  Ten- 
sile, like  transverse  tests,  can  only  be  comparative  in 
the  same  area  or  size  of  test  bars,  see  page  528. 


CHAPTER  LIX. 

CONTRACTION  vs.  STRENGTH  OF  CAST 
IRON.* 

As  to  indicating  unf itness  of  a  test  bar  to  record 

contraction  of  cast  iron,  when  it  has  been  proved 
of  no  value  to  record  strength,  experiments  which 
the  author  has  often  conducted  have  demonstrated  that 
the  percentage  of  combined  or  graphitic  carbon  in  a 
light  casting  or  small  test  bar  can  often  be  regulated  as 
much  by  varying  conditions  in  the  physical  qualities  of 
the  mould  as  by  varying  percentages  in  the  elements 
of  sulphur,  silicon,  manganese,  phosphorus,  etc.,  gen- 
erally contained  in  foundry  pig  metal.  We  will  first 
consider  the  physical  qualities  which  can  affect  the 
strength  of  an  iron,  according  to  the  size  of  a  casting 
or  test  bar,  and  which  is  chiefly  (aside  from  the  '  *  iron  ' ') 
dependent  upon  the  state  of  the  carbon,  whether  it  is 
in  the  combined  or  graphitic  form.  See  page  206. 

Believing  from  the  results  of  previous  experiments  and 
every-day  experience  that  if  the  corners  and  the  cen- 
tral portion  of  square  test  bars  were  analyzed,  a  differ- 
ence would  be  found  existing  in  their  percentage  of 
combined  or  graphitic  carbon ;  also  that  the  combined 
carbon  would  be  less  in  a  one-inch  square  bar  than  in 
a  one-half-inch  square  bar,  both  poured  from  the 

*  Extract  from  a  paper  read  before  the  Foundrymen's  Associa- 
tion, Philadelphia,  Pa.,  Septerrber  4.  1895. 


452  METALLURGY    OF    CAST    IRON. 

same  iron  and  gate,  I  forwarded  the  specimens  of 
which  the  analyses  are  herewith  given  to  the  late  C.  A. 
Bauer,  M.  E.,  general  manager  of  Warder,  Bushnell 
&  Glessner  Co.,  Springfield,  O.,  who  had  his  son, 
Charles  L.  Bauer,  a  chemist,  make  the  determinations 
shown  in  the  following  paragraphs : 

The  specimens  were  one-half  inch  square,  one  inch 
square  and  one  and  one-eighth  inch  round  bars,  belong- 
ing respectively  to  light  machinery  and  chill  roll  iron 
tests,  which  were  among  those  reported  in  my  paper 
before  the  Western  Foundrymen's  Association,  October 
18,  1894,  seen  on  pages  461  and  464.  Paragraph  No.  i 
gives  the  combined  carbon  at  the  corners  and  center  sur- 
face of  the  fracture  of  the  one-inch  square  bars  in  the 
chill  roll  and  light  machinery  mixtures. 

Paragraph  No.  2  is  a  report  of  the  sulphur  contents 
of  the  center  of  the  bars  shown  in  paragraph  i  and 
also  that  of  the  one-half  inch  square  and  one  and  one- 
eighth  inch  round  bars  shown  in  paragraph  3,  which 
were  poured  with  the  same  gate  and  iron  as  those 
in  paragraph  i. 

Paragraph  No.  3  shows  the  difference  in  combined 
carbon  existing  in  the  center  of  the  one-half  inch 
square,  one  inch  square  and  one  and  one-eighth  inch 
round  bars  described  in  paragraphs  Nos.  i  and  2. 

DETERMINATION  No.  i. — Combined  carbon  in  chill 
roll  iron:  At  the  corners,  1.55  per  cent.,  at  the  center 
of  the  fracture,  1.416  per  cent.,  or  .134  per  cent,  more 
combined  carbon  in  the  corners  than  in  the  middle  of 
the  test  bars.  In  light  machinery  iron:  At  the  cor- 
ners, .72  per  cent. ;  at  the  center,  .65  per  cent. ;  or  .07 
per  cent,  more  combined  carbon  in  the  corners  than  in 
the  center  of  the  fracture. 


CONTRACTION    VS.   STRENGTH    OF    CAST    IRON.        453 

DETERMINATION  No.  2. — Sulphur  in  chill  roll  iron: 
At  the  center  of  fracture  in  one-half  inch  square,  .046 
per  cent. ;  one  inch  square,  .044  per  cent. ;  one  and  one- 
eighth  inch  round,  .046  per  cent.  In  light  machinery 
iron:  At  the  center  of  fracture  in  one-half  inch 
square  bar,  .0819  per  cent.  ;  one  inch  square,  .079  per 
cent ;  one  and  one-eighth  round,  .0825  per  cent.  Mr. 
Bauer  writes  that  the  difference  in  sulphur  at  the  cen- 
ter and  the  corners  of  the  different  bars  is  not  percep- 
tible. 

DETERMINATION  No.  3. — Combined  carbon  in  chill 
roll  iron:  In  one-half  inch  square,  2.700  per  cent.; 
one  inch  square,  1.416  per  cent.;  one  and  one-eighth 
inch  round,  1.250  per  cent.  Difference  in  the  extreme 
of  the  combined  carbon  in  the  one-half  inch  square 
and  one  and  one -eighth  inch  round  bar,  1.450  per 
cent.  In  light  machinery  iron:  In  one-half  inch 
square,  .854  per  cent. ;  one-inch  square,  .650  percent. ; 
one  and  one-eighth  inch  round, .  704  per  cent.  Difference 
in  extremes,  .204  per  cent,  of  the  combined  carbon  in 
the  one-half  inch  and  one  and  one-eighth  inch  round 
test  bars  at  their  center  of  fracture.  The  silicon  in 
the  light  machinery  is  1.83  per  cent.  ;  in  the  chill  roll, 
.  7 1  per  cent. 

The  percentage  of  combined  carbon  and  «•  iron  "  in  a 
casting,  etc. ,  chiefly  controls  the  strength  of  the  iron 
and  also  its  contraction.  The  percentages  of  sulphur, 
silicon,  manganese  and  phosphorus  in  cast  iron  are  but 
factors  in  connection  with  the  time  it  takes  a  test  bar 
or  casting  to  solidify  and  become  cold,  determining  the 
degree  to  which  the  carbon  takes  the  combined  form. 

The  above  analyses  plainly  prove  that  a  slight  differ- 
ence in  the  fluidity  of  metal,  or  dampness  in  the 


454  METALLURGY    OF    CAST    IRON. 

"temper"  of  sands,  as  commonly  used  in  ordinary 
foundry  practice,  can  cause  a  radical  difference  in  the 
percentage  of  combined  carbon,  in  the  same  size  and 
form  of  small  castings  or  test  bars  from  the  same 
mixture  of  iron,  poured  out  of  the  same  ladle.  The 
determinations  Nos.  i,  2,  and  3  also  indicate  the  neces- 
sity of  adopting,  for  physical  tests,  the  size  and  form 
of  test  bar  least  liable  to  irregularities  in  the  combined 
carbon  composing  its  shell  or  outer  body,  caused  by 
varying  conditions  in  the  t '  temper  ' '  of  sands  and 
fluidity  of  metals,  etc.  As  degrees  in  the  strength  of 
iron  can  be  affected  b}^  the  * '  temper ' '  of  sand  and 
fluidity  of  metal  at  the  moment  it  is  poured,  so  can 
contraction  records  be  likewise  affected,  making  them 
deceptive.  Experiments  which  I  have  conducted  to 
discover  if  the  same  conditions  which  give  erratic  re- 
sults in  strength  records  would  not  do  likewise  in  con- 
traction, have  only  the  more  confirmed  me  in  the 
advocacy  of  bars  over  one  square  inch  in  area,  wherever 
one  desires  to  be  wholly  or  partially  guided  by  phys- 
ical tests. 

To  learn  whether  differences  in  the  temper  of  sands 
could  cause  changes  in  the  length  of  contraction  in  small 
bars  of  the  same  size,  cast  in  the  same  mould  with  the 
same  iron,  out  of  the  same  ladle,  and  at  the  same  mo- 
ment, I  took  three  patterns  %  inch  square  and  1 2  inches 
long,  and  cast  two  of  them  between  yokes  and  a  third 
bar  in  a  divided  chill  to  form  two  sides  and  bottom  of 
the  mould,  the  fourth  side  being  formed  by  the  sand 
of  the  cope.  The  two  bars  cast  between  yokes  had 
drier  sand  for  one  than  for  the  other.  The  dampest 
sand  was  not  so  damp  but  that  a  sound  casting  could  be 
produced,  and  the  two  sands  differed  no  more  than  can 


OF  THE 

NL 

CONTRACTION  VS.  STRENGTH  OF  CAST 


often  be  found  between  the  *  '  temper  '  '  of  sands  in  one 
shop.  All  three  bars  were  placed  equidistant  in  the 
mould  and  gated  by  means  of  two  upright  "  sprues  M 
which  led  down  to  a  runner  in  the  cope  extending  over 
the  three  bars  in  the  center,  insuring  the  filling  of  the 
three  moulds  at  the  same  time  with  the  same  hand  ladle 
of  iron.  The  test  bars  formed  in  the  chill  and  dampest 
sand  showed  a  greater  contraction  than  the  ones 
enclosed  in  the  driest  sand.  I  have  conducted  quite  a 
number  of  these  tests  and  always  found  in  them  the 
same  results,  those  cast  in  the  chill  showing  the  greater 
contraction.  In  several  cases,  the  extremes  of  one 
flask  gave  a  full  one-sixteenth  inch  difference  in 
the  contraction  of  the  three  bars.  In  the  extremes  be- 
tween the  *  '  temper  '  '  of  the  wetter  and  drier  sand,  I 
have  found  a  difference  of  fully  one  thirty-second  part 
of  an  inch  to  exist  in  the  contraction  of  two  one-half 
inch  bars  poured  from  the  same  hand  ladle  at  the  same 
moment,  thereby  proving  that  a  test  bar  as  small  as 
one-half  inch  square  or  round  is  altogether  too  sensi- 
tive to  variation  in  the  "  temper  "  of  moulding  sand  to 
be  relied  upon  to  afford  any  true  knowledge  of  the 
natural  contraction  of  an  iron. 

To  discover  what  effect,  if  any,  degrees  in  dampness 
or  '  '  temper  '  '  of  sand  have  on  a  round  bar  cast  on 
end,  I  took  a  pattern  one  and  one-eighth  inch  in 
diameter  and  made  a  dry  sand  mould,  using  a  piece 
of  six-inch  gas  pipe  to  mould  it  in,  leaving  both  ends 
open.  After  this  little  mould  was  dried  in  an  oven, 
it  was  set  on  end  upon  a  planed  plate  and  the  distance 
equally  divided  between  two  empty  gas  pipes.  Each 
of  these  two  latter  pipes  was  then  rammed  up  with 
"  green  sand  "  of  a  different  temper.  Each  test  bar 


456  METALLURGY    OF    CAST    IRON. 

had  a  projection  cast  on  the  tipper  end  exactly  two  feet 
from  the  bottom  of  the  mould,  which  was  formed  by 
the  bottom  plate  to  measure  contraction  by.  The  three 
bars  were  poured  by  one  runner  in  the  center  of  the 
three  moulds,  the  iron  dropping  from  the  top.  I  made 
these  three  bars  two  feet  long,  so  as  to  give  a  greater 
length  than  was  in  the  one  foot  long  by  one-half 
inch  square  bars,  to  better  detect  any  difference  that 
might  exist  in  the  contraction  of  the  bars  due  to 
variation  in  the  ' '  temper  ' '  of  the  sand.  When  these 
bars  were  measured,  no  difference  could  be  found  in 
their  contraction  —  a  further  proof  of  the  necessity 
of  using  a  bar  larger  than  one-half  inch  square  or 
round  to  show  the  true  contraction  of  an  iron.  I  also 
made  tests  with  one  and  one-eighth  inch  round  bars 
cast  flat,  but  did  not  find  that  the  radical  variation 
which  existed  in  the  *  *  temper  ' '  of  the  sand  made  any 
difference  in  the  length  of  their  contraction.  Previous 
to  these  tests,  I  also  made  some  in  our  foundry  in  the 
presence  of  E.  Duque  Estrada,  M.  E.,  of  Pittsburg,  a 
member  of  the  American  Society  of  Mechanical 
Engineers'  Testing  Committee,  to  learn  whether 
degrees  in  fluidity  of  iron  would  affect  the  contraction 
of  large-sized  test  bars  or  thick  castings.  To  test  this 
point,  two  bars  two  inches  square  and  forty-eight 
inches  long  were  moulded  together  in  the  same  mould. 
One  was  poured  with  the  metal  as  * '  hot ' '  as  could  be 
obtained  from  the  cupola,  and  the  other  with  the  same 
ladle  cooled  down  to  pour  the  rnetal  as  ' '  dull ' '  as  pos- 
sible and  still  obtain  a  full-run  bar.  Two  sets  of  these 
experiments  were  made,  but  no  difference  was  found 
in  their  contraction.  The  fact  of  there  being  no 
visible  difference  in  the  contraction  of  the  two-inch 


CONTRACTION    VS.     STRENGTH    OF    CAST    IRON.          457 

square  bars  cast  flat,  also  the  one  and  one-eighth  inch 
round  bar  cast  flat  and  on  end,  was  dueto  the  body  of 
the  test  bars  being  sufficiently  massive  to  overcome 
any  tendency  which  variations  in  the  fluidity  of  metal 
or  dampness  of  the  sand  could  exert  in  causing  a 
difference  in  the  combined  carbon.  With  large-sized 
test  bars,  properly  cast,  having  no  corners  to  be  af- 
fected by  the  ' '  temper  ' '  of  sands  and  fluidity  of  metal, 
contrary  to  the  conditions  seen  in  a  square  or  small 
test  bar,  we  are  justified  in  placing  the  utmost  con- 
fidence in  the  record  which  they  may  present.  And 
were  it  not  that  in  accepting  castings  there  is  gen- 
erally a  large  margin  permitting  the  founder  to  often 
greatly  disregard  obtaining  the  best  possible  physical 
properties  of  the  iron  in  his  castings,  the  error  of 
using  bars  as  small  as  one-half  inch  square  or  below 
one  square  inch  area  would  have  been  clearly  demon- 
strated long  before  this.  (See  pages  454,  467,  484,  511 
and  573.) 


CHAPTER  LX. 

COMPARISONS    OF     STRENGTH    IN    SPE- 
CIALTY   MIXTURES.* 

This  chapter  is  a  revised  extract  from  a  report  of  the 

author's  labors  as  a  member  of  the  Western  Foundry- 
men's  Association  Testing  Committee,  and  presents  a 
series  taken  from  about  one  hundred  tests  which 
he  personally  obtained,  of  irons  such  as  are  used  for  gun 
metal,  chill  rolls,  car  wheels,  heavy  machinery, 
light  machinery,  stove  plates  and  sash  weights,  a  list 
which  can  be  seen  to  cover  very  nearly  all  mixtures 
or  "grades"  necessary  to  cast  iron  founding. 

Each  founder  in  casting  a  set  of  these  test  bars  from 
the  patterns  which  the  author  furnished  made  three  one- 
half  inch  square,  three  one  inch  square,  three  one  and 
one-eighth  inch  in  the  rough,  and  three  one  and  one- 
eighth  inch  turned.  These  one  and  one-eighth  inch 
round  bars  in  the  rough  and  turned  are  of  an  area  as 
nearly  equal  to  one  square  inch  as  it  is  practical  to  make 
them.  The  turned  bars  were  cast  with  a  swell  on  so 
as  to  measure  about  one  and  five-eighth  inches  in 
diameter  for  about  four  inches  of  their  length  in  the 
center.  This  swell  was  turned  down  until  the  bars 
measured  close  to  the  size  of  their  companion,  one  and 
one-eighth  rough  bars.  The  comparison  between 

*  Read  at  the  meeting  of  the  Western  Foundry  men's  Associa- 
tion, at  Chicago,  Wednesday  evening,  Oct.  24,  1894. 


STRENGTH    IN    SPECIALTY    MIXTURES.  459 

the  rough  round  and  the  turned  bar  enables  us  to 
perceive  the  difference  that  may  exist  between  the 
strength  of  the  iron  with  its  surface  affected  by  the 
walls  of  a  green  sand  mould  and  that  of  iron  having 
its  rough  surface  turned  off. 

It  was  first  planned  to  have  all  these  test  bars  cast 
on  end,  so  as  to  afford  the  most  favorable  conditions 
to  insure  solid  bars,  etc.,  but  in  starting  with  car 
wheel  mixtures,  difficulty  was  found  in  getting  the 
half-inch  square  test  bars  to  * '  run, ' '  and  as  there 
were  other  strong  irons  I  desired  tests  from,  I  had,  on 
account  of  the  one-half  bars,  to  change  the  plan  of 
casting  and  had  all  bars  cast  flat.  The  three  test  bars 
from  each  of  the  four  sizes  were  cast  all  in  one  flask, 
poured  from  the  same  gate,  and  out  of  the  same  ladle. 

These  test  bars  were  cast  by  some  of  the  most 
prominent  foundry  specialists  in  this  country!  They 
are  not  a  crucible  melt  of  estimated  mixtures  or  of  a 
special  heat,  but  are  taken  from  ' '  regular  heats ' ' 
1 '  run  ' '  for  making  castings  in  the  specialties  herein 
mentioned,  therefore  represent  the  strength  of  the 
actual  metal  used  in  actual  practice  for  the  manufacture 
of  the  castings  outlined  as  far  as  is  practical  with  bars 
cast  flat*  A  complete  chemical  analysis  of  the  various 
mixtures  obtained  in  the  tests  shown  in  this  Chapter 
can  be  seen  on  page  299.  The  analyses  were  all  taken 
from  the  rough  bars  shown  in  the  respective  Tables. 

The  micrometer  measurements  given  in  the  follow- 
ing tables  are  the  average  of  dimensions  taken  from 
the  four  sides  of  the  square  and  round  bars  and  hence 
give  the  size  of  the  test  specimen  in  the  thousandth 
part  of  an  inch.  The  common  rule  measurements 
give  the  size  as  closely  as  it  is  practical  to  roughly 

*  Views  of  the  fractures  of  these  various  irons  are  seen  in  Figs. 
95  to  102,  at  the  close  of  this  chapter. 


460 


METALLURGY    OF    CAST    IRON. 


state  the  dimensions.  All  the  bars  were  cast  15  inches 
long  and  in  breaking  them  for  transverse  strength 
they  rested  on  pointed  supports,  12  inches  centers. 
The  last  two  columns  in  the  Tables  give  the  computed 
relative  strength.  The  outside  column  is  used  only 
for  the  half-inch  square  bars,  so  as  to  illustrate  two 
methods  of  figuring,  and  is  obtained  by  multiplying 
the  breaking  load  by  eight,  a  method  advanced  by 
some,  for  one-half-inch  bars.*  The  inner  is  obtained 
by  the  rules  shown  in  Chapter  LXL,  page  476.  The 
area  of  a  bar  1.1284  inch  in  diameter  is  equal  to  the 
area  of  one  inch  square ;  by  keeping  this  in  mind  the 
figures  in  the  micrometer  columns  can  have  their 
relation  to  a  square  inch  readily  defined. 

TABLE  89.  — TRANSVERSE  TESTS  OF  GUN  METAL. 


1 

6 
fc 

Common  rule 
measure- 
ment. 

Microm't'r 
measure- 
ment. 

Deflec- 
tion. 

Broke  at 
in 
pounds. 

Strength  per 
square  . 
inch 
in  pounds. 

i 

2 

Rough  bars. 
%  in.  square  

.491  in. 
.501   " 

.120  in. 
.115  " 

3/6 
420 

1,560    3,008 
1,673    3,36o 

3 
4 
5 

Planed  bars. 
y?.  in.  square  

ii           « 

.491  in. 
•495  " 
•494  " 

.250  in. 
.270  " 

.200   " 

384 
360 
316 

1,593    3,072 
1,469    2,880 
1,295    2,582 

6 

Rough  bars, 
i  in.  square  

i.  002  in. 

.090  in. 

3,500 

3,486      .... 

996  " 

.o8s  " 

•3,  1,80 

3,400      .... 

8 

"      

1044  " 

•ogs 

3,428 

3,145      -• 

9 
10 
ii 

Planed  bars, 
i  in.  square  

1.007  in. 
1.005  " 
1.005  " 

.130  in. 

.120   " 

.110  " 

3,140 
3,095 
3,072 

3,096      .... 
3,064      .... 
3,042      .... 

12 

Rough  bar. 
i%  in.  diam  

i  132  in. 

.125  in. 

3,708 

3,686    

13 

Turned  bar. 
iJ4  in-  diam. 

1.139  in- 

.150  in. 

3,^20 

3,258    

Test  bars,  Table  44,  were  furnished  by  Builders'  Iron  Foundry,  Providence,  R. 
I.  Tested  by  Thomas  D.  West,  at  the  works  of  the  T.  D.  West  Foundry  Co  , 
Sharpsville,  Pa.,  Sept.  i8th,  1894.  Witnesses,  Geo.  H.  Boyd  andG.  M.  Mcllvain. 

The  first  series  of  tests  we  will  present  is  that  re- 
cording the  strongest  mixture,  seen  in  Table  89 ;  the 

*  By  a  study  of  Chapter  LXL.  it  will  be  seen  that  the  inner  column  referred 
to  above  is  obtained  by  a  rule  that  cannot  be  recommended  for  ^-inch  bars ; 
and  while  that  used  for  the  outside  column  is  preferable,  it  would  be  still 
more  satisfactory  if  it  were  known  that  the  %-inch  bars  did  never  vary  from 
tho  size  of  their  pattern  —  something  which  it  is  not  practical  to  expect 


STRENGTH    IN    SPECIALTY    MIXTURES. 


46l 


second,  the  next  best  in  strength,  and  so  on,  the  last 
Table  being  the  weakest  iron. 

The  test  of  the  gun  metal,  Table  89,  page  460,  showed 
the  planed  bars  of  a  very  coarse  grain  partaking  of  a 
fibrous  nature,  somewhat  after  a  good  grade  of  wrought 
iron,  having  a  fracture  of  a  dark  color.  The  metal 
of  the  rough  bars  showed  the  fracture  in  the  one- 
half-inch  square  bar  to  be  strictly  white  and  in  the 
one-inch  square  test  bars  to  be  of  a  crystalline  mot- 
tled nature,  and  in  the  rough  one  and  one-eighth  inch 

TABLE  90.' — TRANSVERSE  TESTS  OF  CHILL  ROLL  IRON. 


£ 

6 
fe 

Common  rule 
measure- 
ment. 

Microm't'r 
measure- 
ment. 

Deflec- 
tion. 

Broke  at 
in 
pounds. 

Strength  per 
square 
inch 
in  pounds. 

14 

Rough  bars. 
yz  in.  square  

.509  in. 

.120  in. 

230 

888    1,840 

15 

.518  " 

.150  " 

300 

1,119    2,400 

16 

Rough  bar. 
i  in.  square  

1.032  in. 

.120  in. 

2,590 

2,432     

17 

Rough  bar. 
i%  in.  diam  

1.140  in 

.150  in. 

3,040 

2,980     

Tfl 

Turned  bar. 
iJ4  in.  diam  

1.124  in. 

.190  in 

3,020 

3,044     

Test  bars  furnished  by  Lewis  Foundry  &  Machine  Co.,  Pittsburg,  Pa. 
Tested  at  the  works  of  McConway  &  Torley,  Pittsburg,  Pa.,  June  2yth,  1894,  by 
J.  B.  Nau,  Allegheny,  Pa.  Witnessed  by  R.  G.  G.  Moldenke,  K.  M  ,  Ph.  D. 

diameter  bars  of  a  similar  character,  but  to  a  little- 
less  degree  than  shown  in  the  one-inch  square  bars. 
The  large  open-grained  bars,  or  those  of  numbers  3, 
4,  5,  9,  10  and  n,  illustrated  in  Table  89,  were  planed 
from  the  muzzle  disc  of  a  12 -inch  mortar  casting,  and 
bars  i,  2,  6,  7,  8,  12  and  13  were  cast  with  metal 
which  was  used  to  pour  a  lower  base  ring  for  a  12- 
inch  spring  return  mortar  carriage.  The  charge  of 
iron  for  the  mortar  was  very  much  harder  than  that 
used  for  the  base  ring,  but  as  it  was  cast  in  a  very 


462 


METALLURGY    OF    CAST    IRON. 


large  mass  and  cooled  very  slowly  it  is  not  surprising 
that  the  fracture  shows  the  iron  in  the  mortar  body  to 
be  much  softer  (or  open-grained)  than  that  in  the  test 
bars  from  the  base  ring.  The  tensile  strength  of  the 
two  specimens  taken  for  acceptance  of  the  12 -inch  re- 
turn mortar  or  lower  base  casting  as  above  described 
was  as  follows: 


No. 


37,100  Ibs. 


No. 


37,000  Ibs. 


TABLE  91. — TRANSVERSE  TESTS  OF  CAR-WHEEL  IRON. 


1 

1 

Common  rule 
measure- 
ment. 

Microm't'r 
measure- 
ment. 

Deflec- 
tion. 

Broke  at 
in 
pounds. 

Strength  per 
square 
inch 
in  pounds. 

19 

20 

Rough  bars. 
%  in.  square  

.474  in- 
.496  " 

.090  in. 
.ego  " 

273 
280 

1,213    2,184 
1,138    2,240 

21 

"           " 

.491   " 

.090  " 

278 

1,1^8    2,224 

22 

Rough  bars, 
i  in    square     ..  . 

I  OI2  ill. 

.075  in. 

2,535 

2,476    

23 
24 

I  022    " 
I.O07    " 

.074  " 
•075  " 

2,415 
2,294 

2.3p    
2,262     

11 

27 

Rough  bars. 
iya  in.  diam  

1.090  in. 
1.072  " 
I-I35  " 

.iij  in. 

.100    " 

.100  " 

2,340 
2,360 
2,568 

2,508    
2,615    
2,538    

28 

Turned  bar. 
ij4  in    diam 

i  174  in 

170  in 

T,  oso 

2,819    

Test  bars  furnished  by  A.  Whitney  &  Sons,  Philadelphia,  Pa.  Tested  by 
John  R.  Matlock,  Jr.,  at  the  works  of  Riehle  Bros.'  Testing  Machine  Co.,  Phila- 
delphia, Pa.,  June  27th,  1894.  Witness,  W.  C.  Cutler. 

In  the  chill  roll  iron,  Table  90,  page  461,  a  few  of 
the  pieces  were  selected  after  having  been  broken 
for  transverse  strength  and  pulled  for  the  tensile 
strength.  Bar  No.  15  pulled  6,100  pounds;  No.  16 
pulled  23,700  pounds;  and  No.  17  pulled  30,100  pounds. 
The  iron  in  the  half -inch  bars  showed  a  white  crystal- 
line fracture,  likewise  the  one-inch  square.  The  one 
and  one-eighth  inch  diameter  rough  bars  showed  a  very 
close  knit  grain  tending  to  a  light  color.  The  one 
and  one- eighth  inch  turned  bars  are  also  very  close 


STRENGTH    IN    SPECIALTY    MIXTURES. 


463 


grained,  a  little  darker  in  color  than  the  one  and  one- 
eighth  inch  bars,  but  both  of  the  latter  exhibit  to  an 
expert  the  appearance  of  great  strength  as  being  of 
exceptionally  strong  metal. 

The  iron  in  the  car  wheel,  Table  91,  page  462,  shows 
the  half-inch  bars  to  be  white  and  crystalline.  In  the 
one-inch  square  bar  the  iron  is  mottled,  tending  to 
white.  In  the.  one  and  one-eighth  inch  round  rough 
bars  the  metal  is  more  evenly  mottled  and  less  white 
than  in  the  one-inch  square.  The  one  and  one-eighth 
inch  round  turned  bars  show  a  very  rich  dark  gray 
color.  Bar  No.  26  pulled  tensile  23,270.  This  mix- 
ture proved  to  be  an  excellent  iron. 

TABLE  92. — TRANSVERSE  TESTS  OF  HEAVY  MACHINERY  IRON. 


i 

d 
fc 

Common  rule 
measure- 
ment. 

Microm't'r 
measure- 
ment. 

Deflec- 
tion. 

Broke  at 
in 
pounds. 

Strength  per 
square 
inch 
in  pounds. 

29 

30 
3i 

Rough  bars. 
Yz  in.  square  

.504  in. 
•503  " 

•504  " 

.195  in- 

.220   " 
.185    " 

380 
432 

372 

1,496    3,040 
1,707    3456 
1,465    2.976 

32 
33 
34 

Rough  bars, 
i  in.  square  

i  004  in. 
1.009  '' 

1.007  " 

.100  in. 
.090  " 

.ICO 

2,464 
2,510 
2,640 

2,444     
2,465     
2,604     ••-•• 

Rough  bars. 

137  in 

.100  in. 

2786 

2  745 

37 

•135  " 
.143  " 

.120   " 

.100  " 

2,500 

2,791      .... 
2,437      •••• 

38 
39 
40 

Turned  bars. 
\y&    n.  diam  

.125  in. 
.125  " 
.124  " 

.120  in. 
.150  " 
.140  " 

2,257 
2,488 
2,344 

2,271      .... 
2,503      .... 
2,363      ».. 

Test  bars  furnished  by  the  Walker  Manufacturing  Company,  of  Cleveland, 
Ohio.  Tested  by  Thomas  D.  West,  at  the  T.  D.  West  Foundry  Co.,  Sept.  i8th, 
1894.  Witnesses,  Geo.  H.  Boyd  and  G.  M.  Mcllvain. 

The  iron  in  the  above  half -inch  test  bars  presents  a 
very  close,  compact  grain,  tending  to  white.  The  one- 
inch  square  bars  show  a  close,  dense  fracture,  tending  to 
alight  gray  color.  The  one  and  one-eighth  inch  round 


464 


METALLURGY    OF    CAST    IRON. 


bars  are  less  dense  and  present  more  of  a  dark  gray  color 
than  the  one-inch  square  bars.  The  turned  bars  show 
a  fine,  rich-colored,  compact  iron,  such  as  would  stand 
exceptional  wear  and  resistance  to  fracture.  Bar  No. 
34  pulled  26,160  pounds,  and  No.  35,  28,676  pounds. 
For  medium  to  heavy  machinery,  this  metal  should 
make  a  most  serviceable  casting. 

TABLE  93. — TRANSVERSE  TESTS  OF  LIGHT  MACHINERY  IRON. 


1 

6 

fc 

Common  rule 
measure- 
ment. 

Microm't'r 
measure- 
ment. 

Deflec- 
tion. 

Broke  at 
in 
pounds. 

Strength   per 
square 
inch 
in  pounds. 

4i 

Rough  bar. 
%  in.  square  

.499  in. 

.2-0  in. 

454 

1,823    3,632 

42 

Rough  bars, 
i  in.  square..  

1.016  in. 

.130  in 

16 

43 

i  02  1  " 

125  " 

VxA      

44 

"           "          

1.008  " 

.115  " 

1,800 

I.771     

$ 

47 

Rough  bars. 
\Y%  in.  diam  

.146  in. 
.156  " 
.141  " 

.160  in. 
.180  " 
.180  " 

1,795 

2,220 

1,980 

1,741     -   - 
2,115    ••   - 
1,938    ..   .. 

48 
49 

Turned  bars. 
ij/g  in.  diam....  

.162  in. 
160  " 

.200  in. 

1,705 

1,609    ..   .. 
i  628 

50 

"     

•175  " 

.210  " 

1,775 

1,637     »   •• 

Test  bars  furnished  by  Taylor,  Wilson  &  Co  ,  Ltd.,  Allegheny,  Pa.  Tested 
by  J.  B.  Nau,  at  the  works  of  McConway  &  Torley,  June  igth,  1894.  Witness, 
R.  G.  G.  Moldenke,  E.  M.,  Ph.  D. 

The  fracture  of  above  set  of  tests  shows  an  excep- 
tionally good  iron  for  light  work.  The  tests  record 
above  the  average  for  soft  iron  as  regards  strength. 
The  color  is  a  rich  gray,  devoid  of  that  silver  look 
many  castings  display  that  are  desired  to  be  of  a  soft 
quality.  The  half-inch  bars  are  the  closest  grained, 
the  one-inch  square  the  next  in  order,  then  comes  the 
one  and  one-eighth  inch  in  the  rough,  followed  by  the 
turned  one  and  one-eighth  inch  bars,  which  are  the 
most  open-grained,  rich  in  color  and  graphite.  A 
few  of  these  bars  were  pulled  for  the  tensile  strength. 


STRENGTH    IN    SPECIALTY    MIXTURES. 


465 


No.   41   stood  6,000  pounds;    No.   43   stood  a  pull  of 
19,000  pounds,  and  No.  47  separated  at  21,120  pounds. 

TABLE  04. — TRANSVERSE  TESTS  OF  STOVE  PLATE  IRON. 


In 

I 

i 

v 
52 

53 

54 
55 

Common  rule 
measure- 
ment. 

Microm't'r 
measure- 
ment. 

Deflec- 
tion. 

Broke  at 
in 
pounds. 

Strength  per 
square 
inch 
in  pounds. 

Rough  bars. 
y%  in.  square  

•475  in. 
.476  " 
•474  " 

.220  in. 
.260  " 
.250  " 

160 

170 

I'-.O 

711     1,280 
747    1,360 

669       1,200 

Rough  bars, 
i  in.  square  

.994  in. 
•975  " 

.150  in. 

.100    " 

i,757 
i,  660 

1,778       

i,747     

56 

57 

58 
g 

Rough  bars. 
il/s  in.  diam  

.118  in. 
.126  " 

.170  in. 
.170  " 

1,780 

1,775 

1,813     
1,783     

Turned  bars. 
iJ/6  in.  diam  

.127  in. 
.140  " 
.125  " 

.180  in. 
.183  " 
.180  " 

1,320 

1,440 
1,335 

1,322     

I,4'2      

1,343    

(i          « 

Test  bars  furnished  by  Bissell  &  Co.,  Allegheny,  Pa.      Tested  by  J.  B  Nau, 
at  the  works  of  McConway  &  Torley,  June  2oth,   1894.      Witness,  R  G.G. 
Meldenke,  E.  M.,  Ph.  D. 

The  above  tests  of  the  inch  square  and  round  bars 
assert  this  iron  to  be  of  good  strength  for  the  work 
intended.  A  factor  in  this  series  which  will  no  doubt 
attract  attention  is  the  light  load  the  half-inch  bar 
stood  in  comparison  with  the  larger  sizes  and  only 
goes  to  further  demonstrate  the  erratic  and  deceptive 
results  which  we  may  expect  with  small  test  bars.  No. 
53  stood  6,000  pounds  tensile;  No.  54  stood  16,600 
pounds;  and  No.  60  stood  17,150  pounds. 

In  studying  Table  95,  one  is  impressed  with  the 
uniformity  of  the  load  the  bars  stood  and  also  the 
weight  necessary  to  break  them,  for  as  a  general  thing 
' '  white  iron  ' '  exhibits  little  strength  in  castings.  The 
tests  would  lead  us  to  decide  that  the  greatest  weak- 
ening element  in  castings  made  of  "white  iron  "  is 
due  to  excessive  contraction,  which  is  characteristic  of 


466 


METALLURGY    OF    CAST    IRON. 


TABLE  95. — TRANSVERSE  TESTS  OF  SASH  WEIGHT  OR  WHITE    IRON. 


1 

g 

Common  rule 
measure- 
ment. 

Microm't'r 
measure- 
ment. 

Deflec- 
tion. 

Broke  at 
in 
pounds. 

Strength  per 
square 
inch 
in  pounds. 

61 

Rough  bars. 
J^  in.  square  

.488   n. 

.062  in. 

175 

735    1,400 

62 

63 

.484  ; 
.487  • 

.060   ' 
.062   ' 

160 
170 

683    1,280 
717    1.360 

6.) 

Rough  bars, 
i  in.  square  

.992  in. 

.050   n. 

»34° 

,361     

•994    ' 
•992    ' 

.040    ' 
•055    ' 

,325 
,365 

;$  .:::: 

67 

Rough  bars. 
ij4  in.  diam  

1.114  n. 

.050   n. 

>355 

,392    

68 

i  113   ' 

.oss    ' 

44° 

480 

69 

"           "    

1.117   ' 

.050 

,320 

,346    

Test  bars  furnished  by  E.  E.  Brown  &  Co.,  Philadelphia,  Pa.  Tested  by  W. 
C.  Cutler,  at  the  works  of  Riehle  Bros.'  Testing  Machine  Co.,  Philadelphia, 
Pa.,  June  29th,  1894. 

*  *  white  iron. ' '  Many  castings  made  of  white  iron  have 
been  known  to  fly  to  pieces  from  internal  contraction 
strains  when  cooling,  without  a  jar  or  the  least  weight 
being  placed  upon  them.  The  reason  for  not  show- 
ing any  turned  bars  in  this  test  is  due  to  the  diffi- 
culty or  rather  the  impracticability  of  machining  such 
a  hard  metal.  Bar  No.  69  pulled  7,125  pounds.  The 
fracture  of  all  the  bars  is  of  a  very  pronounced  crys- 
talline white  appearance,  as  can  be  seen  in  Fig.ioi 
on  page  473- 

TABLE9&. — SUMMARY  OF  THE  STRONGEST  TESTS. 


No. 
of 
bar. 

Transverse 
Strength  per 
square  inch. 

No. 
of 
bar. 

Tensile 
Strength  per 
square  inch. 

Specialties 
of  mixtures. 

12 

3,686 

*37,ioo 

Gun  Metal. 

17 

2,980 

17 

30,100 

Chill  roll. 

26 

2,615 

26 

23,270 

Car  wheel. 

| 

2,791 
2,115 

35 
47 

28,676 

21,120 

Heavy  machinery. 
Light  machinery. 

56 

1,813 

60 

17,  '5° 

Stove  plate. 

68 

1,480 

69 

7,125 

Sash  weight. 

*Thi»  tensile  test  is  No.  i  of  Mr.  R.  A.  Robertson's  gun  metal  report. 


STRENGTH    IN    SPECIALTY    MIXTURES. 


467 


Having  completed  the  record  of  tests,  it  is  now  in 

order  to  learn  what  they  prove.  It  will  require  but 
little  study  of  the  Tables  to  find  that  the  small  bars  do 
not  record  any  true  variation  in  degrees  of  strength, 
no  matter  what  quality  of  iron  is  used.  They  assert 
that  gun  metal,  chill  roll,  car  wheel  and  heavy  ma- 
chinery are  no  stronger  than  light  machinery  or  soft 
grades  of  irons.  Any  one  experienced  in  the  handling 
or  use  of  cast  iron  knows  that  the  first  four  grades  of 
iron  are  stronger  and  have  a  higher  commercial  value 
for  strength  than  the  fifth  one. 

To  further  illustrate  the  impracticability  of  using 
bars  below  one  square  inch  area,  we  show  an  average 
of  the  strength  of  the  one -half  inch  square  and  one 
and  one-eighth  inch  round  rough  bars  of  all  such  tests 
given  in  this  Chapter  in  the  following  Table  97 : 

TABLE   97— STRONG  IRONS. 


Average  of  %  in. 
square  bars. 

Average  of  i  %  in. 
round  bars. 

Gun  metal...         

3  686  pounds 

265        " 

Chill  roll  

2  980           " 

277        " 

Car  wheel 

2  553        " 

393        " 

Heavy  machinery  

2,657        " 

WEAK  IRONS. 


Average  of  ^£  in. 
square  bars. 

Average  of  i  %  in. 
round  bars. 

i  931  pounds 

160 

.Stove  plate        

1,798        " 

167 

Sash  weight  

1,406 

It  cannot  but  be  plain  from  the  averages  in  Table  97 
that  the  half-inch  square  bar  is  a  size  readily  af- 
fected by  the  least  change  in  the  dampness  of  sands  or 


468  METALLURGY    OF    CAST    IRON. 

fluidity  of  metal,  to  afford  any  fair  knowledge  of  the 
true  relative  differences  in  strength  of  cast  iron. 
The  half-inch  -bars  from  gun  metal  and  the  half- 
inch  bars  from  heavy  machinery  practically  show 
each  to  be  of  the  same  strength,  where  the  one  and 
one-eighth  round  bars  indicate  what  we  would  nat- 
urally expect,  namely,  that  the  gun  metal  is  materi- 
ally stronger  than  the  heavy  machinery  iron.  Then 
again,  the  half-inch  bars  would  indicate  that  the  heavy 
machinery  iron  was  very  much  stronger  than  the  roll 
irons.  The  strength  of  the  half-inch  bars  for  light 
machinery,  454  pounds,  indicates  such  iron  to  be 
stronger  than  gun  metal,  chill  roll,  car  wheel  or  heavy 
machinery  iron,  while  the  one  and  one-eighth  inch 
round  bars  show  the  light  machinery  to  be  but  1,931 
pounds,  as  compared  with  3,686  pounds  for  gun  metal, 
2,980  pounds  for  chill  roll,  2,553  pounds  for  car  wheel 
and  2,657  pounds  for  heavy  machinery.  The  half-inch 
bars  show  a  breaking  load  of  160  pounds  for  stove 
plate  and  167  pounds  for  sash  weight  or  **  white  iron," 
indicating  that  the  latter  is  the  stronger  iron,  while 
our  one  and  one-eighth  inch  round  bars  show  a 
strength  of  1,798  pounds  for  stove  plate,  and  only  1,406 
pounds  for  sash  weight  iron,  thus  thoroughly  demon- 
strating that  one  inch  square  area  bars  will  fairly  record 
the  true  relative  degrees  of  strength  of  cast  iron, 
whereas  the  half -inch  square  bar  gives  us  absolutely 
little  knowledge  or  indication  of  any  difference  in 
strength  between  one  mixture  and  another,  or  any 
irons  used  in  the  different  specialties  of  iron  founding. 
A  fact  that  further  demonstrates  the  impracticability 
of  using  small  test  bars  is  that  the  tensile  strength  of  the 
Table  96  records  a  uniformity  in  degrees  of  strength 


STRENGTH    IN    SPECIALTY    MIXTURES.  469 

closely  corresponding  with  the  transverse  load  of  one 
square  inch  area  bars  in  the  same  Table,  and  which 
would  have  been  still  better  could  the  bars  only  have 
been  cast  on  end. 

The  next  size  and  form  of  bar  to  consider  is  that 
of  the  one-inch  square.  In  comparing  the  fracture  of 
the  square  with  those  of  the  round  bars  (see  pages  472 
and  473),  the  grain  of  the  former  will  average  denser 
and  all  square  bars,  excepting  those  of  '  *  white  iron  ' ' 
fracture,  show  the  bars  to  be  much  denser  at  the  cor- 
ners than  on  the  flat  surface  section  of  the  bars,  thereby 
giving  a  less  uniform  grain  and  causing  more  in- 
ternal strains  in  a  square  bar.  They  are  also  weaker 
than  a  round  bar.  This  point  the  records  of  Table 
98  fully  prove,  by  showing  that  the  round  bars  record 
a  greater  strength  than  square  bars  of  like  areas.  I 
do  not  wish  to  be  understood  as  saying  we  should 
adopt  the  method  which  will  show  the  greatest 
strength  in  the  bar,  but  rather  the  one  best  to  insure 
knowledge  of  the  natural  relative  qualties  of  cast 
iron  mixtures,  and  this  the  round  bar  will  do. 

TABLE    98. — SUMMARY    OF     BEST     STRENGTH    AVERAGES    OF    ROUGH 
ROUND  VS.   SQUARE  TEST  BARS. 


Gun  metal                         Average  of  1^5  in   round  bars 

3  686  Ib 

"        "                                     "          "    i  in.  square  bars 

Chill  roll                                   "          "    il/z  in-  round  bars  

2  080 

"         "     ...           .                      "            '    i  in.  snuarebars 

2  4^2 

Car  wheel  " 

'   iJ/&  in.  round  bars 

'   i  in.  square  bars 

2  350 

Heavy  machinery  " 

'   il/z  in.  round  bars       .  . 

..2  657 

'   i  in  square  bars  

Ivight  machinery  " 

'   il/z  in.  round  bars  

I.931 

'    i  in   square  bars 

70S 

Stove  plate   " 

'   i  J4  in.  round  bars 

708 

'   i  in  square  bars  .. 

761 

Sash  weight   " 

'    iT%in    round  bars 

406 

"           "     ,  "          "   i  in.  square  bars  

>o 

470  METALLURGY    OF    CAST    IRON. 

This  Chapter  presents  facts  which  should  greatly  aid 
in  settling  all  disputes  as  to  the  value  of  the  round  over 
the  square  bar  for  recording  the  best  natural  strength 
of  cast  iron,  and  that  we  should  not  use  a  bar  less 
than  of  one  square  inch  area.  *  The  tests  exhibited  are 
all  of  sound  fracture,  and  in  all  bars  but  those  for 
sash  weight  iron  could  be  machined  as  described  on 
page  300.  For  tests  of  larger  round  bars  than  one  and 
one-eighth  inch  diameter,  and  a  discussion  on  the 
utility  of  test  bars,  see  pages  533,  536,  577  and  579. 

Previous  to  this  series  of  tests,  etc. ,  being  first  pub- 
lished, the  author  had  no  knowledge  of  any  person 
thinking  to  advance  information  on  the  physical  prop- 
erties of  cast  iron,  working  other  than  in  one  "grade," 
and  drawing  conclusions  from  this  as  being  applicable 
to  anything  that  might  come  under  the  head  of  cast 
iron,  which  is  a  broad  term  and  means  any  "grade" 
that  the  metalloids,  silicon,  sulphur,  phosphorus  and 
manganese  when  combined  with  metallic  or  ' '  pure 
iron,"  make  workable  for  conversion  into  castings. 
While  it  is  true  the  quality  of  ' '  grades  ' '  being  in  cast 
iron  was  not  recognized  as  it  should  be  by  experi- 
menters, etc.,  making  or  reporting  physical  tests,  the 
author  is  pleased  to  note  that  this  work  has  "caused 
cognizance  being  taken  of  this,  as  such  a  course  places 
all  in  a  position  to  arrive  at  correct  conclusions  to  the 
sooner  fathom  any  phenomena  that  may  puzzle  or 
make  mysterious  the  workings  of  cast  iron.  It  would 
be  well  to  study  Chapter  XX.  in  connection  with  this 
paragraph. 

A  study  of  the  cuts  seen  in  Figs.  95  and  102  will 
show  how  the  metal  is  best  permitted  to  have  its 

*The  American  Foundrymen's  Association  adopted  resolutions  that  test 
bars  smaller  than  ij^-inch  diameter  were  not  recognized,  see  pages  573,  577 
and  579. 


STRENGTH    IN    SPECIALTY    MIXTURES.  471 

carbon  evolve  uniformly  in  the  graphitic  form,  by 
the  use  of  the  round  test  bar,  hence,  again  showing 
this  to  be  the  best  form  which  we  could  adopt  for 
obtaining  knowledge  of  the  relative  strength,  etc., 
of  cast  iron.  It  will  be  seen  that  by  a  use  of  the  one- 
half  square  bar  with  weak  irons,  the  carbons  remain 
mostly  in  the  combined  state,  and  when  used  for 
strong  iron,  its  body  becomes  "white"  or  crystalline. 
In  the  one-inch  square  bars  the  corners,  as  may  be 
seen,  are  much  deeper  in  combined  carbon  or  dense 
in  grain  than  on  the  flat  surface,  as  seen  at  A  B,  Figs. 
97  and  98,  and  instead  of  its  skin  or  shell  being  an 
even  thickness  or  of  a  uniform  texture,  as  seen  in  the 
round  bars  at  D  and  E,  Figs.  97  and  98,  it  is  very  ir- 
regular. Furthermore,  although  the  square  bars  are 
of  about  the  same  area  as  the  round  bars,  still  we  find 
the  latter  has  the  greatest  body  of  metal  in  the  gra- 
phitic form. 

Complete  analyses  of  all  the  specialties  here  exhib- 
ited in  combination  with  others  are  presented  in  Chapter 
XLIV.  These  will  assist  in  defining  the  percentage  of 
chemical  properties  best  to  exist  in  an  iron  or  mixtures 
to  secure  the  various  physical  conditions  and  qualities 
desired  in  castings  at  the  present  day.  Nos.  29  and  30, 
Fig.  102,  illustrate  the  affinity  of  iron  for  sulphur,  being 
the  bars  described  in  Chapter  XXX. ,  in  which  sulphur 
or  brimstone  was  placed  in  the  ladle  after  No.  30  had 
been  poured.  The  white  ring  at  H,  No.  29,  shows  the 
hardening  effect  of  sulphur. 


PIG.  95. — GUN  METAL.      SILICON  1. 19;   SULPHUR  .055. 


No.  2.  No.  3.  No.  4.  No.  5. 

FIG.  96. — CHILL  ROLL.       SILICON  .77;   SULPHUR  .058. 


No.  6. 


No.  7. 


No.  8. 


No.  9. 


FIG.  97. — CAR  WHEEL  IRON.       SILICON  .66;    SULPHUR  .127- 

D 


D 


B 


No.  10.  No.  ii.  No.  12.  No.  13. 

FIG.  gg. — HEAVY  MACHINERY  IRON.       SILICON  1.50;    SULPHUR  .IIO. 


No.  14. 


No.  15. 


No.  1 6. 


No.  17. 


FIG.  99 LIGHT  MACHINERY.      SILICON  1.83;   SULPHUR  .078. 


No.  18.  No.  19.  No.  20.  No.  21. 

FIG,  IOO.— STOVE  PLATE  IRON.       SILICON  2.59;    SULPHUR  .072. 


No.  22.  No.  23.  No.  24.  No.  25. 

FIG.  101.—  SASH  WEIGHT  IRON.       SILICON.  l8o;    SULPHUR.  138. 


No.  26.  No.  27.  No.  28. 

FIG.  102.— SULPHUR  TEST. 


No.  29. 


No.  30. 


CHAPTER  LXI. 

COMPUTATION  OF  RELATIVE  STRENGTH 
OF  TEST  BARS. 

The  rule  for  computing  the  relative  strength  of  test 
bars  (see  page  476)  is  to  divide  the  breaking  load  by 
the  area  of  the  bar,  at  its  point  of  fracture.  It  is  to 
be  understood  that  this  rule  can  be  applied  only  to  bars 
of  the  same  length  and  cross  section,  or  made  from 
the  same  pattern,  in  sizes  or  areas  to  equal  1^6  inch  to 
2^/2.  inches  diameter  or  such  bars  as  shown  on  pages 
536  and  573,  for  the  purpose  of  making  compari- 
sons of  any  difference  that  may  exist  in  the  area  of 
test  bars  made  from  off  the  same  pattern,  due  to  a 
straining,  etc. ,  of  the  mould  in  which  the  bars  were 
cast.  While  the  compilation  derived  by  the  rules  in 
Table  99,  page  476,  are  placed  under  the  head 
of  * '  Strength  per  square  inch  ' '  in  most  of  the  Tables 
of  tests  in  this  work,  such  is  given  as  a  matter 
of  form,  or  for  relative  comparisons,  and  not  as 
absolute  strength  per  square  inch.  The  author 
has  .  presented  the  rule  given  in  Table  99  for  the 
reason  that  it  is  the  simplest  for  ordinary  shop 
testing,  and  takes  better  cognizance  of  the  prac- 
tical elements  for  everyday  use  in  a  standard  bar 
than  any  other  formula  of  which  he  has  knowledge. 
Whatever  systems  are  advanced  for  making  relative 
comparisons  in  the  transverse  or  tensile  strength  of 
iron,  no  matter  what  size  of  a  bar  we  use,  be  it  of  one 
inch,  two  inches,  or  three  inches  area,  square  or  round, 
the  author  claims  that  none  should  be  recognized  as 


RELATIVE  STRENGTH  OF  TEST  BARS.         475 

worthy  of  any  serious  consideration  as  a  standard  that 
requires  us  to  take  into  account  more  than  one-eighth 
inch  from  the  size  of  the  test  bar  pattern  used.  The 
moment  we  attempt  to  figure  up  or  down,  to  determine 
a  metal's  strength  per  square  inch,  or  the  more  we  are 
diverted  from  the  exact  size  of  the  bar  actually  tested, 
the  more  we  will  err  in  drawing  correct  comparative 
deductions  in  any  "  grade "  of  iron.  In  order  to 
obtain  a  relative  knowledge  of  the  strength  of  an  iron 
we  must  confine  tests  to  the  use  of  one  size  of  a  bar 
(see  page  534),  let  that  be  a  one-inch,  two-inch,  or  three- 
inch  square  area  bar,  and  its  computation  should  only  be 
permitted  in  taking  into  account  any  variations  which 
may  exist  due  to  irregular  work  in  the  moulding  and 
casting  of  any  one  of  the  three  sizes  that  may  be  used. 
In  testing  bars,  this  effect  from  irregularity  in 
moulding  which  can  cause  a  variation  in  the  size  of 
test  bars,  made  off  from  the  same  pattern,  should  be 
taken  note  of  in  compiling  any  records  of  strength 
filed  for  reference  or  comparison.  Note  should  be 
taken  of  the  least  variation  which  might  exist  in 
the  size  of  a  standard  test  bar,  as  a  few  thousandths 
part  of  an  inch  in  the  diameter  of  a  bar  is  multi- 
plied about  three  times  in  its  circumference.  A 
little  variation  in  the  size  of  a  test  bar  can  make  a 
bar  considerably  stronger  or  weaker,  according  as  its 
diameter  is  decreased  or  increased  from  the  size  of  the 
pattern  from  which  the  test  bars  are  moulded.  In  com- 
piling this  work,  it  will  be  observed,  that  the  author 
has  thought  it  correct  to  recognize  this  factor,  and  hence 
the  adoption  of  the  column,  "  Strength  per  square 
inch, ' '  seen  with  some  of  the  tables  given  herewith. 
In  order  that  the  reader  may  understand  how  any 


METALLURGY    OF    CAST    IRON. 

difference  in  the  relative  strength  of  test  bars 
was  obtained  for  the  tables,  we  give  two  examples 
seen  on  this  page,  as  one  method  is  necessary 
for  a  square  bar  and  another  for  a  round  bar  :  The 
author  could  never  perceive  wherein  the  formulae 
used  for  figuring  the  strength  per  square  inch,  as 
advanced  by  our  text  books,  etc.  ,  had  any  bearing  on 
the  actual  area  of  a  test  bar  and  the  load  at  which  it 
broke;  in  fact,  if  in  1901  a  founder  should  send  the 
area  and  tests  of  round  and  square  test  bars  to  recog- 
nized authorities  on  mathematics  to  have  their  strength 
per  square  inch  computed,  the  chances  are  they  would 
present  such  figures  that  he  would  be  liable  to  wonder 
if  present  formulae  for  cast  iron  were  not  invented 
rather  for  the  purpose  of  distorting  facts  or  making 
figures  lie  than  for  furnishing  true  data.  The  author 
has  referred  to  this  subject  on  several  occasions  since  he 
published  the  methods  for  computation  shown  in  table 

TABLE   99.  —  SQUARE   BAR.       TEST    NO.    6.         PAGE    460. 


Area  of  bar. 

1.002  in.     x     1.002  in.       =        1.004  square  inches. 
Breaking  load.  Area. 

3,500  Ibs.  -±-       1.004  =  3>486  Ibs.  strength  per  sq.  in. 

ROUND   BAR.       TEST   NO.    12.       PAGE   460. 
Diameter.    Diameter.  Square  of  diameter. 

1.132  in.    x     1.132  in.       =        1.281424  square  inches. 
Square  of  diam.  Decimal.  Area. 

1.281424  x          .7854       =       i.  006  square  inches. 

Breaking  load.  Area. 

3,708  -r-          1.006       =       3,686  Ibs.  strength  per  sq.  in. 

99,  and  was  pleased  to  note  that  at  the  meeting  of 
the  American  Society  of  Mechanical  Engineers,  St. 
Louis,  May,  1896,  Prof.  C.  H.  Benjamin  came  out 
openly  in  a  letter  discussing  the  testing  of  cast  iron 
and  attacked  the  usual  formulae  for  loaded  beams  as 


RELATIVE  STRENGTH  OF  TEST  BARS.        477 

being  incorrect,  insisting  that  a  reform  should  be 
enacted  in  this  field  of  mathematics.  In  his  letter  he 
expressed  the  opinion,  as  stated  by  the  American 
Machinist,  that  the  terms  ''modulus  of  elasticity," 
"elastic  limit,"  etc.,  were  entirely  out  of  place  as 
applied  to  cast  iron,  and  should  not  be  used  at  all  in 
connection  with  that  material,  and  that  the  usually 
accepted  formulae  for  strength  of  beams  would  not  hold 
good  for  cast  iron  beams,  as  had  been  shown  by  tests 
made  by  himself  for  the  committee. 

The  author  trusts  that  the  good  work  started  at  St. 
Louis  will  result,  before  many  years,  in  our  having 
some  standard  for  computing  the  strength  of  cast  iron 
that  can  be  recognized  as  more  practical  or  more  cor- 
rect than  our  present  formulas  for  figuring  different 
lengths  and  sizes  of  bars  or  loaded  beams.  It  is  as 
essential  to  have  correctness  in  formulas  for  figuring 
the  strength  of  cast  iron  as  it  is  to  have  correct  systems 
for  casting  and  testing  such  grades  of  metal.  (See 
page  530.) 

To  any  desiring  to  use  larger  bars  than  the  one 
and  one-eighth  inch  diameter  shown  in  Table  99,  and 
wishing  to  keep  even  figures  as  with  a  two -inch  or 
three-inch  area  section,  as  some  may  desire  to  do,  the 
only  difference  would  be  to  have  the  figures  1.596  or 
I-955>  as  the  case  may  be,  replace  the  1.128,  which  is 
the  diameter  of  a  bar  equal  to  the  area  of  a  one-inch 
square  bar.  It  may  be  well  to  mention  at  this  point 
that  the  Riehle  Bros,  of  Philadelphia  and  others  now 
use  the  method  for  computing  the  strength  of  test  bars 
shown  in  Table  99,  page  476. 


CHAPTER  LXII. 

VALUE    OF   MICROMETER    MEASURE- 
MENTS  IN  TESTING. 

"  What  is  worth  doing  at  all,  is  worth  doing  well," 

is  an  old  maxim,  and  never  more  applicable  than  to  the 
subject  of  testing.  It  can  be  readily  observed  that 
the  author  is  an  advocate  of  utilizing  every  factor 
that  can,  in  any  manner,  assist  in  lessening  erratic 
records  and  advance  testing  of  cast  iron  to  its  high- 
est perfection.  Such  advocacy  would  be  inadequate 
did  the  author  not  argue  for  the  adoption  of  the  mi- 
crometer to  measure  the  area  of  test  bars  at  the  point 
of  fracture.  The  micrometer  would  be  used  much 
more  than  it  is  at  the  present  time,  did  testers  only 
more  fully  realize  the  difference  a  few  thousandths  of 
an  inch  in  the  diameter  of  a  bar  can  make  in  the 
strength  records,  especially  when  the  same  are  re- 
duced to  make  relative  comparison  of  strengths. 

Many  would  be  surprised  to  learn  how  often  they 
have  been  deceived  in  according  differences  in  strength 
to  records  obtained  simply  by  calipers  and  common  rule 
in  considering  the  size  of  bars  for  comparisons.  If  the 
micrometer  had  been  used  and  the  area  reduced  to 
make  relative  comparisons  as  illustrated  on  page 
475,  testers  would  ofttimes  have  found  bars,  which 
were  conceded  by  the  breaking  load  records  to  be  the 
strongest,  to  prove  the  weakest  test  of  iron. 


VALUE    OF    MICROMETER    MEASUREMENTS.  479 

It  is  impossible  to  obtain  rough  bars  of  the  same 
area.  There  is  sure  to  be  some  difference  in  their 
sizes.  It  is  not  unusual  to  find  one-inch  area,  etc., 
bars  to  be  from  one-sixteenth  to  one-eighth  larger  in 
diameter  or  the  square  than  the  pattern  used  and  to 
find  that  testers  make  no  note  of  such  difference,  but 
are  wholly  guided  by  the  weight  at  which  the  bar 
broke.  If  one  was  one  hundred  or  two  hundred  more 
than  others,  the  highest  was  accepted  as  the  strongest 
and  best  test,  regardless  of  the  bar's  exact  area. 

To  illustrate  how  a  small  bar  breaking  with  a  heavier 
load  than  the  large  bar  (each  differing  but  a  few  thoii- 
sandths  of  an  inch  in  their  area),  may  often,  if  not  re- 
duced to  relative  strengths,  etc.,  deceive  a  tester 
200  to  400  pounds  in  accepting  common  rule  measure- 
ment and  the  actual  load  in  thinking  he  has  a  true 
record  of  the  iron's  strength,  the  reader  is  referred 
to  Table  89,  tests  Nos.  6  and  8,  on  page  460,  showing 
transverse  tests  of  gun  metal.  There  we  find  two 
bars  which,  if  the  actual  breaking  loads  were  accepted, 
would  deceive  the  tester  269  pounds,  or  in  other  words, 
instead  of  his  believing  he  had  one  bar  only  72  pounds 
stronger  than  the  other,  he  actually  had  a  difference  of 
269  pounds,  as  stated  above.  This  should  aid  to  clearly 
illustrate  the  importance  of  micrometer  measure- 
ments, wherever  the  tester  desires  to  truly  ascertain 
whether  any  difference  actually  exists  in  the  strength 
of  his  mixtures  or  the  character  of  the  iron  produced. 

Another  feature  well  to  be  noticed  is  that  of  the 
impractibility  of  obtaining  bars  exactly  round  or 
square,  or  exact  duplicates  of  their  pattern.  Many 
testers  take  but  one  measurement  of  a  bar,  while  others 
take  no  measurement  at  all.  Any  following  either 


480  METALLURGY    OF    CAST    IRON. 

practice  might  almost  as  well  omit  their  testing,  for 
they  are  as  liable  to  be  misled  as  be  correct  in  their 
conclusions.  In  obtaining  the  area  of  a  round  or 
square  bar  two  measurements,  at  least,  should  be 
taken,  added  together,  and  then  divided  by  two  to 
obtain  the  average  of  their  sizes  to  assure  a  tester  that 
he  has  knowledge  of  what  is  closely  the  true  total  area 
of  bars.  Those  desirous  of  closely  following  mixtures, 
etc. ,  by  physical  tests  to  obtain  true  knowledge  of  the 
strength  of  their  product,  can  not  ignore  the  value 
of  micrometer  measurements.  For  scientific  research, 
at  least,  such  methods  must  be  strictly  followed.  To 
find  decimal  equivalents  for  use  in  micrometer  measure- 
ments, see  Table  139,  page  594. 


CHAPTER  LXIII. 


OPERATING  TESTING  MACHINES. 

Obtaining  true  results  or  close  records  in  testing  is 
often  assisted  as  much  by  careful  work  and  system  in 
operating  testing  machines  as  by  correct  methods  in 
the  moulding,  casting,  etc. ,  of  test  bars. 

In  obtaining  the  transverse  strength  and  deflection 
of  bars  cast  flat  they  should  always  be  laid  on  the  bear- 
ing blocks  the  same  way.  The  importance  of  this  is 
realized  when  we  consider  that  the  down  or  ' '  nowel ' ' 
side  of  a  one-inch  area  round  or  square  bar  can  be 
made  to  show  a  strength  of  300  to  400  pounds  more 
by  having  the  ' '  nowel ' '  side  resting  on  the  blocks 
than  where  the  cope  side  is  so  placed,  a  quality  clearly 
proven  in  Chapter  LXV.,  page  488. 

If  bars  are  cast  on  end,  it  is  well  to  have  the  down  or 
upper  cast  end  always  pointed  the  same  direction.  *  To 
insure  this  in  the  methods  advocated  by  this  work,  a 
small,  flat  depression  is  cast  in  the  bars,  so  as  to  permit 
their  always  finding  a  good  bearing  at  the  same  spot 
of  the  bars,  as  seen  at  X,  Fig.  103,  next  page. 

The  same  speed  in  testing  should  always  be  main- 
tained as  far  as  possible,  as  whether  a  bar  is  broken 
fast  or  slowly  can  make  a  difference  in  results.  A 
comfortable  speed,  which  can  be  always  readily  main- 
tained, should  be  adopted.  In  obtaining  tensile 

*This  is  essential,  as  it  assists  in  obtaining  an  approximate 
area  at  the  breaking  point,  as  the  taper  of  the  patterns  and  strain- 
ing of  the  mould  from  head  pressure  are  liable  to  make  the  area 
of  the  bars  vary  at  different  heights. 


482 


METALLURGY    OF    CAST    IRON. 


strength  of  test  bars,  every  care  should  be  taken  to 
prevent  one  side  being  strained  or  pulled  more  than 
the  other.  The  grip  should  be  such  as  to  cause  an  even 
pull  all  over  the  area  of  the  specimen,  in  order  to  ob- 
tain the  true  tensile  strength  of  the  iron.  See  page  450. 
Another  essential  in  operating  testing  machines  is 
that  of  applying  the 
weight  as  steadily  as 
practicable.  At  Fig. 
104  is  shown  the  up- 
per section  of  a  type  X 
of  testing  machine 

now  being  largely  used,  in  which  the  oscillation  of 
the  beam  F,  from  the  lower  stop  H  up  to  the  up- 
per stop  K,  in  some  cases  may  mean  a  load  of  100 
pounds,  which  if  brought  up  or  down  quickly  re- 
sults in  a  strain  like  an  impact  blow.  A  good  plan  to 
follow  in  using  a  machine  of  this  design  is  to  place 
one  hand  around  the  stop  at  K.  By  this  plan,  less 
room  is  allowed  for  the  oscillation  of  the  weighting 


FIG.    103. 


beam  and  the  hand  readily  informs  the  mind  of  any 
upper  movement,  so  that  the  sliding  poise  can  be 
made  to  balance  the  beam  before  a  bar  could  break 
to  make  it  questionable  within  one  hundred  pounds  of 
just  what  is  its  true  strength,  by  reason  of  the  beam 
F  rising  suddenly  to  the  stop  K. 


CHAPTER  LXIV. 

ROUND  vs.   SQUARE  TEST  BARS.* 

The  square  test  bar,  cast  flat,  was,  prior  to  1890, 
almost  solely  employed.  The  author  first  advocated 
the  use  of  a  round  test  bar  in  an  article  in  the  A  meri- 
can  Machinist,  June  6,  1889.  He  is  aware  that  the 
square  bar,  cast  flat,  has  been  the  basis  of  elaborate 
tables  of  transverse  strength  for  use  by  engineers,  etc., 
and  for  publication  in  our  scientific  text-books ;  yet,  in 
spite  of  all  this,  the  practice  is  wrong. 

Metal,  in  cooling,  arranges  its  crystals  in  lines  per- 
pendicular to  the  bounding  planes  of  the  mass,  or,  in 
other  words,  the  crystals  arrange  themselves  along  the 
lines  the  waves  of  heat  travel  in  passing  outward  from 
the  casting  as  it  cools  off.  To  assist  in  illustrating  this 
subject  I  have  taken  the  following  description  and  cuts 
(Figs.  105  and  106)  from  Spretson's  work  on  founding. 
Speaking  of  the  cuts,  Mr.  Spretson  says : 

In  the  round  bar  the  crystals  are  all  radiating  from  the  center. 
In  the  square  bar  they  are  arranged  perpendicular  to  the  four 
sides,  and  hence  have  four  lines,  in  the  diagonals  of  the  square, 
in  which  terminal  planes  of  the  crystals  abut  or  interlock,  and 
about  which  the  crystallization  is  always  confused  and  irregular. 

This  is  said  to  be  very  plainly  exhibited  by  the  effect 

*  A  revised  extract  of  a  paper  read  before  the  Western  Foundry- 
men's  Association,  June,  1894. 


484 


METALLURGY    OF    CAST    IRON. 


of  manganese  in  steel  castings  showing  a  contrast  be- 
tween round  and  square  fractures. 

A  study  of  Figs.  105  and  106  impresses  one  with  the 
importance  of  arranging  for  the  greatest  possible  uni- 
formity in  providing  for  the  radiation  of  heat  from  a 
test  specimen,  and  also  to  afford  it  the  most  favorable 
condition  to  arrange  its  crystals  uniformly  through- 
out its  body.  It  requires  no  great  stretch  of  the  imag- 
ination to  conceive  what  a  great  influence  the  simple 
matter  of  slight  differences  in  the  ' '  temper  ' '  of  sand 
in  a  mould  may 
have  in  causing 
non-uniformity  in 
the  even  texture 
of  a  square  bar 
compared  to  the 
even  structure 
possible  in  a  round 
bar.  Mr.  John  E. 
Fry,  in  a  paper  before  the  Eastern  Association,  May  2, 
1894,  condemning  one-half  inch  square  test  bars,  clearly 
illustrates  the  effect  of  a  little  variation  in  the  "  tem- 
per ' '  or  dampness  of  sand,  often  making  small  bars 
wholly  unreliable  as  a  test  for  the  relative  strength 
of  any  kind  of  cast  iron. 

Before  leaving  Figs.  1 05  and  1 06,  let  me  call  attention 
to  their  clear  exemplification  of  the  necessity  of  cast- 
ing test  bars  on  end,  in  order  to  insure  uniform  cool- 
ing off.  The  heavy-work  founder  knows  that  metal 
first  solidifies  at  the  bottom  of  a  mould,  and  if  he  is 
"feeding"  a  heavy  casting,  the  metal,  by  solidifying 
at  the  bottom  first,  will  gradually  force  his  "  feeding 
rod ' '  upward,  thus  demonstrating  that  the  greatest 


FIG.  105. 


FIG.   1 06. 


ROUND    VS.     SQUARE    TEST    BARS.  485 

line  for  radiation  or  line  for  heat  to  escape  is  upward, 
or  through  the  ' '  cope  "  of  a  mould.  For  this  reason, 
if  we  would  break  a  casting  a  foot  -square  into  halves 
down  the  center  of  its  vertical  position,  as  when  cast, 
we  would  find  the  last  spot  to  solidify  would  gener- 
ally be  about  three  inches  from  the  top,  or  one-fourth  its 
height  below  the  cope  surface.  It  makes  no  difference 
how  small  a  body  of  metal  may  be,  the  same  principle 
is  applicable  to  it  as  to  the  large  body,  and  goes  to 
fully  demonstrate  the  irregularity  for  a  central  point 
of  latest  solidification  which  must  exist  in  a  test  bar 
cast  flat.  Then  again,  uneven  cooling  is  bound  to 
cause  more  or  less  internal  contraction  strain  in  a  test 
bar.  It  must  be  evident  that  a  test  bar  cast  on  end 
will  have  an  even  radiation  from  all  portions  of  its 
surface  at  any  height,  and  thus  give  to  the  bar  the 
best  uniform  grain  throughout  any  section  and  also 
the  best  opportunity  to  lessen  strains  so  far  as  cooling 
off  has  any  effect.  More  information  on  the  necessity 
of  casting  test  bars  on  end  will  be  found  in  the  next 
Chapter,  page  488. 

The  nature  of  all  cast  iron  is  such  that  any  elements 
in  a  mould  possessing  heat-conducting  powers,  that 
will  either  chill  or  make  closer  the  grain  of  the  metal 
in  the  skin  or  surface,  are  very  effective  in  changing 
results  in  the  strength  and  contraction  of  iron,  espe- 
cially in  light  castings  or  small  test  bars.  There  is  a 
great  difference  in  iron  in  its  susceptibility  to  elements 
tending  to  chill.  Some  iron,  if  poured  into  a  dry  sand 
mould,  would  show  a  gray  fracture,  but  if  poured  into  an 
iron  or  green  sand  mould,  would  show  at  the  surface  a 
white  or  chilled  iron,  the  depth  of  which  depends  upon 
the  character  of  the  iron,  the  thickness  of  castings, 


486  METALLURGY    OF    CAST    IRON. 

etc.  In  Fig.  107,  we  see  an  irregular  circle,  outside  of 
which  we  find  the  deepest  close-grained  sections  at 
the  corners  A  B.  The  lower  the  ' '  grade  ' '  of  the 
iron  and  the  damper  the  sand  the  deeper  will  these 
corners  chill  or  close  up  the  grain  of  an  iron.  There  is 
a  limit  to  the  extent  to  which  combined  carbon  shown 
in  the  closing  of  the  outer  grain  can  cause  strength 
in  the  test  bar,  where  it  is  combined  with  a  soft  center 
or  graphitic  core  as  seen  at  D.  A  test  bar  can,  by  a 
radical  difference  in  the  grain  of  the  core  and  outer 
body,  embody 
such  contraction 
strains  within  its 
own  elements  as  to 
break  with  a  light- 
er load  compared 
with  the  true  natu- 
ral qualities  of 
metal  as  exhibited  FIG-107' 

by  actual  working  results  in  castings  or  from  a  turned 
test  bar.     Degrees  in  "temper"  or  dampness  of  the 
sand    comprising   a  mould,  have   every   influence   in 
changing  results   in   the   corners   of  a   test   bar.     A 
square  bar  is  an  erratic  bar  at  its  best ;  one  cannot  say 
what  it  will  do  in  often  showing  different  grades  of 
iron  to  be  partly  the  opposite  of  what  a  use  of  the 
castings  would  demonstrate.     This  is  especially  true 
where  square  test  bars  are  cast  flat. 

We  will  now  turn  our  attention  to  the  round  bar, 
Fig.  1 08.  It  surely  requires  but  little  observation  to 
impress  one  with  the  regularity  of  its  outline  compris- 
ing the  surface  or  close-grained  metal ;  and  it  appears 
like  adding  insult  to  injury  to  discuss  the  favorable 


ROUND    VS.     SQUARE    TEST    BARS.  487 

conditions  it  presents  over  a  square  bar  in  permitting 
iron  to  show  a  uniform  grain  in  a  test  specimen.  No 
one  need  accept  the  illustration  of  this  question  as  ex- 
hibited by  the  cuts  (Figs.  107  and  108),  as  any  founder 
can  cast  square  and  round  test  bars  to  ascertain  the  dif- 
ference in  the  grain  of  two  such  fractures  for  himself. 

For  testing  iron,  by  means  of  rough  cast  bars,  I  am 
at  a  loss  to  conceive  how  any  one  with  the  facts  before 
him,  as  herein  set  forth,  can  scientifically  support  or 
argue  for  the  adoption  of  a  square  test  bar.  When  we 
consider  the  uniformity  of  radiation,  crust,  and  grain, 
that  a  round  bar  cast  on  end  makes  practicable,  and 
then  look  at  a  square  bar  cast  flat,  it  does  seem  that  we 
do  not  need  any  science  but  that  a  little  use  of  fair 
reasoning  is  all-sufficient  to  guide  us  aright  in  deciding 
which  of  the  two  forms  is  the  more  liable  to  most 
closely  approximate  comparisons  of  the  strength  or 
contraction  of  iron  mixtures,  etc. 

The  Author's  continued  advocacy  of  the  round  bar, 
cast  on  end,  since  1889  has  been  rewarded  by  the 
American  Foundrymen's  Association,  at  its  annual 
convention  in  1901,  unanimously  passing  resolutions 
recommending  the  round  bar  cast  on  end  as  the  most 
suitable  for  testing  cast  iron.  This  resolution  also 
recommends  that  bars  should  not  be  smaller  than  one 
and  one-half  inches  diameter.  The  sooner  all  come  to 
recognize  the  advisability  of  adopting  the  above  recom- 
mendations, though  many  may  desire  to  use  as  small 
as  i  y%  -inch  diameter  bars,  which  may  often  be  permis- 
sible with  soft  grades,  the  better  for  all  interested  in 
or  making  use  of  test  records.  An  account  of  the  A. 
F.  A. 's  work  in  bringing  about  the  above  recom- 
mendations is  found  in  Chapter  LXX.,  pages  574  to  584. 


CHAPTER  LXV. 

DISCOVERY  OF  EVILS  IN  CASTING  TEST 
BARS  FLAT. 

At  the  meeting  of  the  American  Society  of  Mechan- 
ical Engineers  held  in  New  York  City  the  week  of 
December  3,  1894,  the  author,  in  a  discussion  on  test- 
ing, briefly  called  attention  to  the  series  of  tests  seen 
on  page  493.  Before  asking  the  reader  to  review  the 
tests,  the  author  wishes  to  comment  on  principles 
involved  arid  what  they  demonstrate  to  us  in  emphat- 
ically proving  that  certain  practices  some  follow  are 
not  correct.  It  is  well  known  that  the  past  practice 
in  moulding  test  bars  has  been  upon  the  principle  of 
casting  them  flat,  and  also  that  the  form  generally 
used  has  been  square  or  rectangular  in  preference  to 
the  round  form  cast  on  end  which,  the  author  is  pleased 
to  note,  has  attracted  much  attention  and  is  now  (1901) 
adopted  by  many  as  the  only  correct  method  to  test 
the  physical  properties  of  cast  iron.  The  author  will 
now  advance  more  proofs  to  show  that  the  round 
test  bar  cast  on  end  is  the  best  method  which  we 
can  adopt  to  reduce  erratic  results  in  testing  to  the 
minimum. 

Early  in  1894,  the  author  discovered  that  in  testing 
a  bar  cast  flat  for  its  transverse  strength,  by  applying 
the  load  on  the  upper  cast  surface  a  much  greater 


EVILS    OF    CASTING    TEST    BARS    FLAT.  489 

strength  could  be  obtained  than  if  the  bar  was  turned 
the  reverse  side  up.  I  have  found  in  experimenting 
with  a  large  number  of  bars  one-half  inch  square,  one 
inch  square,  and  one  and  one-eighth  inches  diameter, 
with  supports  twelve  inches  apart,  that  I  obtained  on 
an  average  30  pounds  more  strength  for  a  one -half  inch 
square  bar,  100  pounds  in  the  one-inch  bar,  and  150 
pounds  in  the  one  and  one-eighth  inch  round  bar.  I 
wish  these  figures  to  be  accepted  only  as  an  average  of 
many  tests  of  bars  of  the  respective  sizes  given,  and 
with  which,  as  a  rule,  the  results  have  been  very  erratic. 

I  have  found  in  a  one-half-inch  square  bar  as  much 
as  50  pounds  difference  in  testing  the  two  sides  and  in 
the  one-inch  square  and  one  and  one-eighth  inch  round 
I  have  found  a  few  bars  which  showed  from  300  to  400 
pounds  difference,  thereby  presenting  proof  that  cast- 
ing flat  any  form  of  size  of  bar  admits  of  errors  and 
jugglery  and  is  wholly  wrong. 

I  would  state  that  in  experimenting  with  testing  on 
the  lower  and  upper  sides  of  test  bars,  they  should 
always  be  moulded  in  the  same  flask,  poured  from  the 
same  ladle  and  from  the  same  gate.  To  prove  my 
position  on  this  question,  I  would  first  call  attention  to 
conditions  which  can  be  found  by  any  who  are  suffi- 
ciently interested  to  experiment  in  this  line.  In  Fig. 
109,  next  page,  is  shown  a  side  elevation  of  a  bar  resting 
on  pointed  supports  A  B,  1 2  inches  apart,  the  distance 
which  the  author  used  in  his  experiments.  The  point 
of  load  is  shown  at  D.  The  position  of  the  bar  is  the 
same  as  when  cast  or  lying  in  its  mould.  In  examin- 
ing such  a  bar  it  will  be  found  that  the  metal  at  the 
lower  side  or  shell  E  E  is  generally  denser,  or  of  a 
closer  grain,  than  that  composing  the  upper  half  of  the 


49° 


METALLURGY    OF    CAST    IRON. 


bar.  This  is  caused  by  the  lower  half  being-  cooled 
more  quickly  than  the  upper  half.  This  gives  in  the 
lower  half  of  the  bar,  in  a  sense,  more  combined  than 
graphite  carbon,  which  results  with  iron  not  ' '  white  ' ' 
in  causing  the  '  *  lower  ' '  half  to  be  of  greater  strength 
than  the  upper  half.  But  the  degree  to  which  this  is 
affected  in  flat-poured  bars  is  largely  controlled  by  the 
difference  in  the  ''temper"  of  the  sand,  hardness  of 
ramming,  degree  of  fluidity,  speed  of  pouring,  and 
the  quality  of  iron  used.  Since  these  conditions  can- 


FIG.  109. 


not  be  always  the  same,  results  in  testing  flat  cast  bars 
are  erratic.  That  one  side  of  a  flat  cast  bar  will  always 
be  in  line  of  giving  more  strength  than  another,  is 
understood  when  we  take  into  consideration,  with 
the  above,  the  fact  that  in  testing  for  transverse 
strength,  we  subject  the  under  side  of  the  bar  to  an 
extension  or  tensile  strain,  and  the  upper  side  to  one 
of  compression  or  crushing.  If  we  have  the  densest 
or  highest  combined  carbon  side  of  a  bar  to  resist 
the  extension,  or  tensile  strain,  it  is  reasonable  to 


EVILS    IN    CASTING    TEST    BARS    FLAT.  491 

expect  it  to  stand  a  greater  load  than  if  we  placed 
the  most  open-grained  or  weakest  side  to  the  ex- 
tension or  tensile  pull.  Another  point  which  proves 
that  there  is  a  difference  in  the  cross  sections  of  the 
grain  of  iron  in  a  test  bar  poured  flat  is  that  if  we  drill 
into  the  end  of  such  bars  there  will  be  found,  as  a  gen- 
eral thing,  a  tendency  for  the  drill  to  work  itself  more 
to  the  top  or  weak  side  of  the  test  bar,  as  more  clearly 
illustrated  in  Fig.  no.  I  cannot  conceive  why  the 
adoption  of  the  round  bar  cast  on  end  should  not 
greatly  lessen  the  causes  for  the  past  erratic  results  in 
testing,  as  my  experience  with  these  bars  so  cast 
makes  it  manifest  how  closely  two 
bars  of  *  like  area,  which  have  been 
properly  cast  on  end,  in  the  same 
flask,  with  the  same  gate  and  out 
of  the  same  ladle,  will  come  to 
each  other.  Table  103,  page  493,  is 
an  example  of  how  closely  round 
bars  cast  on  end  can  record  like 
FIG.  no.  strength.  I  would  call  attention  to 

the  test  of  twelve  bars,  comprising  four  one-half  inch 
square,  four  one  inch  square  and  four  one  and  one- 
eighth  inch  diameter,  which  were  all  moulded  in  one 
flask,  poured  with  the  same  ladle  from  the  same  gate  and 
cast  flat,  as  seen,  page  493,  and  then  compare  the  four  one 
and  one-eighth  inch  round  bars,  which  are  moulded  two 
in  a  flask,  upon  the  principle  which  the  author  advances 
for  casting  test  bars  on  end.  These  were  cast  out  of  the 
same  ladle  after  the  above  twelve  bars  were  poured 
flat.  The  ladle  for  pouring  the  above  sixteen  bars  held 
about  150  pounds  of  metal.  It  will  be  seen  by  the 
examination  of  Tables  100,  101,  and  102  that  all  the 


492  METALLURGY    OF    CAST    IRON. 

bars  cast  flat  stood  the  greatest  load,  with  their  side 
which  was  down  when  cast  being  in  extension  when 
tested,  and  also  that  the  greatest  difference  in  this  re- 
spect exists  in  the  round  bar.  Again  I  would  call  at- 
tention to  the  fact  that  the  results  in  all  the  flat  cast 
bars  were  very  erratic.  This  Table  compares  very 
closely  in  averages  with  a  large  number  of  tests  which 
I  have  made  on  this  point  to  satisfy  myself  as  to  the 
correctness  of  such  results,  and  they  always  point  in 
one  direction. 

A  deceptive  point  which  it  might  be  well  to  notice  in 
casting  test  bars  flat  is  the  chance  it  affords  of  making  a 
test  bar  record  too  great  a  strength  for  an  iron.  Take 
a  round  bar  cast  flat  and  test  it  with  its  side  cast  down 
in  extension,  or  as  illustrated  in  Fig.  109,  page  490,  and 
one  can  record  a  greater  strength  than  by  any  other 
method  of  casting ;  but  where  one  desires  to  record  the 
honest  and  natural  strength  of  an  iron,  he  should  use 
the  round  bar  cast  on  end.  And  by  a  comparison  of  the 
round  bar  cast  on  end  with  those  cast  flat,  as  seen  by 
Tables  1 02  and  1 03,  next  page,  the  system  which  the  au- 
thor advocates  is  found  to  be  one  which  will  not  permit 
a  tester  to  obtain  a  greater  strength  than  that  which  the 
iron  truly  possesses,  nor  admit  of  any  jugglery  in  re- 
cording tests.  When  it  is  known  that  one  side  of  a  flat 
cast  bar  can  often  give  300  to  400  pounds  more  strength 
than  its  opposite  side,  there  is  surely  an  opening  for 
deception  and  variable  results.  The  mixture  of  iron 
charged  for  the  test  on  next  page  was  all  pig  metal  of 
the  analysis  seen  in  Table  104.  The  analysis  of  the 
test  bars  shows  the  silicon  to  be  reduced  ten  points  and 
the  sulphur  doubled  by  re -melting  the  iron. 


EVILS    IN    CASTING    TEST    BARS    FLAT.  493 

TABLE  100.— TRANSVERSE   TESTS    OF    j£/x    SQUARE   BARS    CAST   FLAT. 


°S 
l~ 

Mode  of  test- 
ing. 

Micrometer 
measure- 
ment. 

Deflec- 
tion. 

Broke 
at 
in  Ibs. 

State  of 
fracture. 

Strength 
per  W  sq. 
in  Ibs. 

I 

Top  up. 

•504 

.180 

264 

Sound. 

260 

2 

" 

•509 

.170 

260 

** 

251* 

3 

Top  down. 

.160 

240 

" 

233 

4 

.526 

.no 

160 

Small  flaw. 

M5 

Difference  in  strength  extremes  of  sound  bars,  27  Ibs.  or  11.59  per  cent. 
TABLE  101.— TRANSVERSE   TEST   OF    l"   SQUARE    BARS    CAST   FLAT. 


•3- 
$ 

Mode  of  test- 
ing. 

Micrometer 
measure- 
ment. 

Deflec- 
tion. 

Broke 
at 
in  Ibs. 

State  of 
fracture. 

Strength 
per  sq.  in. 
in  Ibs. 

5 

Top  up. 

i.  022 

.110 

1,784 

Sound. 

1,709 

6 
7 

Top  down. 

1.052 
1.044 

.120 
.120 

1,820 
1,764 

« 

1,645 
1,618 

8 

1.024 

.IOO 

i,  600 

1,526 

Difference  in  strength  extremes,  183  Ibs.  or  11.99  per  cent. 
TABLE  IO2.— TRANSVERSE    STRENGTH    OF    I/X   ROUND    BARS    CAST  FLAT. 


*Sj 
c| 

Mode  of  test- 
ing. 

Micrometer 
measure- 
ment. 

Deflec- 
tion. 

Broke 
at 
in  Ibs. 

State  of 
fracture. 

Strength 
per  sq.  in. 
in  Ibs. 

9 

Top  up. 

1.161 

.160 

2,128 

Sound. 

2,010 

10 

ii 

Top  down. 

1.140 
1.171 

.150 
.140 

1,980 

ii 

1,940 
1,853 

12 

1.131 

.100 

1,682 

1,674 

Difference  in  strength  extremes,  336  Ibs.  or  20  7-100  per  cent. 


TABLE  103.— TRANSVERSE   TESTS   OF    I 


ROUND    BARS    CAST   ON    END. 


<b 

O+; 

l« 

Mode  of  test- 
ing. 

Micrometer 
measure- 
ment. 

Deflec- 
tion. 

Broke 
at 
in  Ibs. 

State  of 
fracture. 

Strength 
per  sq.  in. 
in  Ibs. 

First  flask. 

13 

M 

Cope  side 
Nowel  side 

i.  in 
1.116 

.no 

.110 

1,760 
1,772 

Sound. 

1,815 
1,812 

Second  flask. 

15 

Nowel  side 

1.132 

.in 

1,772 

H 

1,761 

16 

Cope  side 

1.  121 

.no 

1,720 

" 

1,743 

494 


METALLURGY    OF    CAST    IRON. 


Difference  in  strength  extremes  of  two  flasks,  72  Ibs.  or  4.13  per  cent.,  but 
the  greatest  difference  in  one  flask,  tests  Nos.  15  and  16,  and  which  is  the  way 
Table  58  should  be  shown,  is  but  1.03  per  cent. 

Tested  by  Thos.  D.  West,  October  23,  1894,  assisted  by  C.  B.  Kantner,  at 
Sharpsville,  Pa. 

TABLE  104. 


Chemical  analysis  of  pig  iron  charged. 

Chemical  analysis  of  test  bars. 

Silicon. 

1.48 

Sulphur. 
.019 

Mang. 
•35 

Phos. 
.097 

Silicon. 
1.38 

Sulphur. 
.038 

Mang. 
•31 

Phos. 
•099 

A  study  of  the  tests  on  page  493  shows  that  the  great- 
est difference  in  one  flask  of  the  strength  extremes  of 
the  bars  cast  on  end  is  but  1.03  per  cent. ,  compared  with 
11.59,  11.99  and  20.07  Per  cent,  found  in  the  bars  cast 
flat.  It  may  be  well  to  mention  again  the  fact  that  all 
the  bars  were  poured  out  of  the  same  ladle  and  that  the 
flat  cast  bars  were  all  moulded  and  cast  together  in 
one  flask,  giving  them  a  much  better  chance  to  be 
uniform  than  the  bars  cast  on  end,  as  the  latter  were 
cast  in  separate  flasks. 

When  a  system  is  obtained,  where  with  two  bars  cast 
together,  there  will  only  be  three  pounds  of  differ- 
ence in  their  breaking  loads  per  square  inch,  as  is 
found  with  tests  Nos.  13  and  14,  Table  103,  the  author 
has  a  suspicion  that  it  is  about  time  some  were  making 
a  study  of  the  elements  bringing  about  such  close  re- 
sults.* The  difference  of  72  pounds  between  the  two 
flasks  poured  on  end,  shown  in  Table  103,  could  be 
charged  to  the  difference  in  the  fluidity  of  the  metal, 
which  existed  through  lapse  of  time  in  pouring  the  two 
moulds,  a  quality  affecting  the  strength,  etc.,  of  test 
bars  more  fully  defined  on  pages  372  and  526.  Addi- 
tional information  on  casting  test  bars  on  end  will  be 
found  on  pages  508  and  512. 

*  These  two  tests  are  given  merely  to  show  the  close  results 
that  can  be  obtained,  in  a  general  practice,  much  better  with 
round  bars  than  with  square  ones. 


CHAPTER  LXVI. 

PHYSICAL  TESTS   FOR  THE   BLAST-FUR- 
NACE,   AND   THEIR   VALUE.* 

Progress  in  the  science  of  either  making  or  mixing 
iron  requires  a  study  of  the  physical  as  well  as  the 
chemical  properties.  The  importance  of  a  correct  sys- 
tem for  such  tests,  to  make  comparison  possible  be- 
tween different  furnaces,  or  the  same  furnace  at  differ- 
ent times,  or  with  founders,  is  self-evident. 

The  first  point  to  mention  is  the  value  of  re-melting 
samples  of  the  furnace-casts.  The  occasional  re-melting 
of  samples  of  casts,  in  a  small  cupola,  cannot  but  aid 
the  advancement  of  research,  and  serve  as  a  check  on 
chemical  analyses,  and  often  as  a  protection  to  the  fur- 
naceman,  by  enabling  him  to  learn  what  the  founder 
can  do  in  changing  the  character  of  iron  after  it  has 
left  the  furnace  yard.  A  little  cupola  will  also  often 
be  convenient  for  casting  small  pieces  for  repairs  that 
may  be  needed  between  the  furnace-casts,  or  when  a 
furnace  is  out  of  blast. 

A  furnaceman  is  often  not  informed  of  complaints 
concerning  his  iron  until  it  has  been  all  melted  up ; 
and  then  he  has  generally  no  remedy  other  than  to  in- 
spect the  casting's  claimed  to  have  been  made  from 

*  Extract  of  a  revised  paper  read  at  American  Institute  of 
Mining  Engineers'  Meeting,  Pittsburg,  Feb.,  1896. 


496  METALLURGY    OF    CAST    IRON. 

the  iron  complained  of.  As  a  founder,  I  know  there 
are  ways  in  which  the  original  character  of  pig  metal 
can  be  so  altered  in  mixtures  as  to  place  upon  the 
furnaceman  the  blame  for  bad  results  for  which  he  is 
not  justly  responsible.  In  such  cases,  the  remelting 
of  a  sample  by  him  might  often  exonerate  him.*  The 
expense  of  a  small  sample  cupola  need  not  alarm 
any  furnaceman ;  he  can  erect  one  for  twenty  dollars. 
In  fact,  the  author  erected  one  at  the  Spearman  Fur- 
nace, Sharpsville,  Pa.,  January  17,  1896,  which  did  not 
cost  six  dollars,  and  took  but  seven  hours'  labor  of 
one  man  from  the  time  ground  was  broken  until  the  cu- 
pola was  at  work.  A  cast  was  made  in  ten  minutes  after 
the  iron  was  charged.  This  cupola  was  made  of  an 
old  shell,  twelve  inches  in  diameter  and  thirty  inches 
long,  which  was  lying  around  in  our  foundry  yard. 
It  had  been  used  a  few  years  previously  in  an  industrial 
street  parade,  for  casting  horseshoes,  which  were 
thrown  to  the  people  as  the  wagon  went  along,  the 
blast  being  furnished  by  means  of  an  old  pair  of  hand- 
bellows.  If  iron  can  be  melted  under  such  conditions, 
in  such  a  baby  cupola,  no  one  need  hesitate  to  believe 
that  it  can  be  conveniently  done  in  a  small  cupola  at  a 
blast  furnace,  where  all  the  blast  required  can  be 
steadily  supplied. 

The  following  Tables  105,  106,  and  107,  seen  on  next 
page,  give  chemical  and  physical  tests  of  a  furnace- 
cast,  taken  January  18,  1896,  at  the  Spearman  furnace, 
Sharpsville,  Pa.,  and  is  chiefly  given  to  present  one 
good  form  for  such  records: 

*  If  founders  knew  that  f urnacemen  tested  •  their  own  iron  by 
remelting  it  in  a  cupola  and  kept  a  regular  record  of  all  their 
tests,  it  would  have  a  great  tendency  to  make  many  investigate 
thoroughly  to  find  whether  the  fault  was  not  their  own  before 
entering  complaints  to  the  f  urnacemen. 


PHYSICAL    TESTS    FOR    THE    BLAST    FURNACE,    ETC.    497 


TABLE    IO5. —  PHYSICAL   TESTS      OF     FURNACE     IRON     TAKEN     JANUARY 

1 8,  1896. 


No.  of 
Test. 

Contrac- 
tion. 

Deflec- 
tion. 

Strength 

Fluidity. 

Chill. 

Diam'ter 
of  Bar. 

Strength 
per  sq.  in. 

L 

Inch. 
6-64 

Inch. 

O.I2 

Pounds. 
2,300 

Inches. 
41A 

Not 
taken. 

Inch. 
1.194 

Pounds. 

2.054 

TABLE    106. — PHYSICAL   TESTS  OF    CUPOLA-IRON. 


No.  of 
Test. 

Contrac- 
tion. 

Deflec- 
tion. 

Strength 

Fluidity. 

Chill. 

Diam'ter 
of  Bar. 

Strength 
per  sq.  in. 

Pounds. 
1,907 

2 

Inch. 

8-64 

Inch. 
0.08 

Pounds. 
2,220 

Inches, 
5 

Not 
taken. 

Inch, 
1.242 

TABLE    107. 
ANALYSIS  OF    FURNACE-IRON.  ANALYSIS   OF   CUPOLA-IRON. 


Silicon. 

Sulphur. 

Silicon. 

Sulphur, 

Per  cent. 

i.  02 

Per  cent. 
0.034 

Per  cent. 

0.81 

Per  cent. 

0.056 

NOTE. — The  number  of  inches  given  under  "fluidity"  in  this  record  is 
directly  measured  on  the  fluidity  strip,  seen  at  S,  in  Figs.  121  and  122,  pages 
509  and  514. 

The  day  is  past  for  tolerating  the  blind,  ignorant 
practice  which  we  foundrymen  followed  up  to  about 
1890  in  mixing  iron.  The  wonder  is  that  we  ever 
"  hit  "  what  we  wanted,  when  we  consider  how  decep- 
tive is  the  fracture  of  pig  metal  as  a  guide  to  its  true 
"  grade. "  I  am  aware  that  up  to  1900  a  little  over  half 
our  founders  kept  up  with  the  progress  of  utilizing 
chemistry  in  mixing  their  iron;  nevertheless,  I  say, 
when  the  furnaceman  has  done  his  part,  let  the  founder 
study  to  do  his  by  calling  chemistry  to  his  aid,  or  else 
get  out  of  the  business  and  stop  complaining  about 
"bad  iron."  There  is  no  "bad  iron"  in  the  sense 
some  have  inferred.  All  can  be  utilized  in  some  class 


49^  METALLURGY    OF    CAST    IRON. 

of  work  or  other.  All  that  is  wanted  is  a  knowledge 
of  its  chemical  and  physical  properties ;  and  when  the 
furnaceman  and  founder  understand  these  as  they 
should,  pig1  iron  of  any  ' '  grade  ' '  or  quality  need  never 
be  shipped  to  the  wrong  customer.  It  is  simply  a 
question  of  '  *  carding  the  car  ' '  right,  to  have  a  furnace- 
man clean  his  yards,  and  have  no  complaint  about  his 
iron,  however  * '  bad  ' '  he  may  occasionally  make  it,  if 
he  will  but  give  a  correct  analysis. 

The  foundry  iron  of'the  analysis  in  Table  107  is  an 
excellent  grade  to  make  a  machinable,  strong  casting 
for  very  heavy  work,  such  as  should  not  be  under  three 
inches  thick  in  its  lightest  part,  if  all  pig  be  used ;  but 
if  the  furnaceman  gets  the  wrong  shipping  card  on  such 
a  car  of  iron,  and  some  unprogressive  founder  receives 
the  iron,  and  because  it  may  look  "  soft  "  or  "  open- 
grained  ' '  tries  to  mix  one-third  scrap  with  it,  for  light 
or  medium  castings,  he  abuses  the  furnaceman,  be- 
cause his  castings  crack  and  come  out  '  *  white  iron. ' ' 

The  cupola  illustrated  on  page  501  is  the  smallest  I 
know  of  now  used  for  practical  purposes.  Before 
taking  a  * '  heat ' '  out  of  this  small  cupola,  there  was 
but  one  point  that  I  felt  doubtful  about,  in  practice 
with  such  a  small  size  for  the  work  I  intended  it  to 
perform,  and  that  was,  whether  it  would  increase  the 
sulphur,  by  remelting,  more  or  less  than  is  done  on 
an  average  in  the  large  cupolas  commonly  used. 

Owing  to  records  of  cupola  mixtures  kept  at  our 
foundry  since  1892,  or  of  the  analyses  of  the  pig  metal 
that  go  to  make  exacting  work  (in  which  only  shop- 
scrap  can  be  utilized),  and  of  the  castings  produced, 
we  are  enabled  to  judge  fairly  of  the  increase  of  sul- 
phur by  remelting,  and  found  by  comparison  that  the 


PHYSICAL    TESTS    FOR    THE    BLAST    FURNACE,    ETC.     499 

increase  in  sulphur  caused  by  remelting  in  the  small 
cupola  cannot  be  regarded  as  any  greater  than  would 
result  from  remelting  in  large  cupolas.  If  anything, 
it  is  a  little  below  what  might  be  expected  with  fair 
usage.  This  is  due  to  the  iron  not  remaining  in  the 
baby  cupola  as  long  as  in  ordinary  foundry  cupolas. 

I  will  now  proceed  to  describe  a  system  of  testing 
which  I  installed  at  the  Spearman  furnace  at  Sharps- 
ville,  Pa.,  January  17,  1896,  in  which  the  managers 
took  great  interest  and  used,  without  a  doubt,  with 
much  pront  to  themselves. 

The  outfit  includes  one  Olsen  transverse  testing  Hid- 
chine  of  standard  make,  one  cupola,  two  flasks,  and 
chill  pig-moulds  with  a  test  bar  pattern  and  mould- 
board.  An  excellent  feature  of  the  whole  equipment 
is  that  it  need  not  cost  over  one  hundred  dollars, 
including  the  testing  machine.  The  price  of  such  an 
outfit  is  no  more  than  a  furnace  might  have  to  pay  for 
freight  on  one  or  two  cars  of  condemned  iron. 

The  cupola.  Fig.  in  shows  the  cupola  used.  It  may 
have  a  ' '  drop  bottom, ' '  as  shown,  or  it  may  simply 
rest  upon  a  plain  plate,  and  be  tipped  by  hand  to  clean 
it  out,  after  the  conclusion  of  heats.  The  figure  itselt 
explains  all  details  necessary  to  the  construction  and 
plan  of  charging  the  cupola,  as  seen  on  next  page. 

The  cold  blast  is  used  so  as  to  be  the  same  as  in 
foundry  practice.  It  may  require  a  few  trials  to  find 
out  what  pressure  of  blast  will  give  the  best  results. 
It  should  not  exceed  eight  ounces  pressure  at  the 
cupola,  and  will  generally  be  found  to  work  best  at 
about  six  ounces,  where  two  one-inch  tuyeres  are  used. 
Where  a  low  pressure  of  about  four  ounces  can  be 

*If  one  is  inexperienced  in  managing  cupolas,  I  would  advise 
the  cupola  being  14  inches  inside  diameter  instead  of  10  inches, 
as  shown,  and  increasing  the  tuyere  area  30  per  cent. ;  that  is, 
if  a  novice  desires  to  use  the  smallest  cupola  practical  for  melting 
small  samples. 


500  METALLURGY    OF    CAST    IRON. 

well  maintained,  I  would  advise  the  two  tuyeres  being 
about  two  inches  diameter,  and  give  this  plan  the  pref- 
erence over  one-inch  tuyeres  with  higher  blast  press- 
ures. 

The  cupola  should  have  its  bed  of  coke  well  on  fire 
before  the  iron  is  charged,  and  the  latter  should  be 
distributed  evenly  all  over  the  surface  of  the  bed,  the 
largest  pieces  being  placed  in  the  middle.  I  have 
melted  one-quarter  of  a  common-sized  pig  all  down  in 
fifteen  minutes  from  the  time  it  was  charged.  This 
is  mentioned  merely  to  show  that  the  baby-cupola  can 
deal  very  rapidly  with  chunks  of  iron. 

The  melted  iron  should  be  held  in  the  cupola  until 
one  charge  is  thought  to  have  been  all  melted  down, 
before  it  is  tapped  out.  A  charge  of  iron  may  range 
from  20  to  50  pounds;  and  several  charges  may  fol- 
low, having  a  layer  of  coke  between  them,  from  four 
to  five  inches  in  thickness.  For  a  heat  over  twenty 
minutes  long,  some  good  flux  may  be  advantageously 
used  to  make  a  thin  slag,  which  could  be  run  off  at 
the  tap-hole  or  at  a  slag-hole,  provided  for  the  purpose, 
about  two  inches  above  the  level  of  the  tap-hole.  To 
start  the  blast  it  is  usually  best  to  let  the  lowest 
pressure  of  blast  found  permissible  with  utility  left 
on,  up  to  the  time  that  about  two  pounds  of  melted 
iron  run  out  of  the  tap-hole.  After  this  flowing  of 
metal,  plug  up  the  hole  and  increase  the  blast  pressure 
a  few  ounces,  so  as  to  bring  down  the  iron  quickly,  and 
collect  it  in  a  good  body,  which  will  maintain  its  fluid- 
ity while  it  remains  on  the  bottom  bed  before  being 
tapped.  In  letting  out  the  fluid  metal,  make  a  large 
hole  and  have  a  warm  ladle  to  receive  the  liquid  iron. 

The  lining  used  for  the  cupola  is  simply  a  coating  of 


* 

I 

Second  charge  of  coke. 

1 

4 

3 

Second  charge  of  iron. 

( 

' 

* 

'/, 

/  > 

First  charge  of  coke. 

t 
1 

= 

E_ 

First  charge  of  iron. 

r 

" 

'  - 

1) 

Bed  of  coke. 

\ 

'•• 

*                               m"                               » 

.'•• 

--              't 

i 

•'•  •  •:--. 

>v 

0  

; 

•i^. 

X-"" 

.^ 

• 

prasTO 

V"*Pr^^r^Y^rj2^^ 

i    j 

• 

f"    v'^/ 

1 

• 

e==^  — 

FIG.    III. 

u 

—  -*^. 

1  ;'•':•»  «':'.•.'•  •:•::••••:.•.•.•.  =  :  :  •  •  R^\^SSS1  •  •  ••  •••;'.it:  ••••.•:•:  •'  .'•'•  ••::''-i;'-'-'£Sr'&2\2  '•'.•"•  r  ••.••'•  ."••••."•.  v..-.vs 

K& 

502  METALLURGY    OF    CAST    IRON. 

fire  clay,  from  three-fourths  to  one  inch  thick.  It 
could,  of  course,  be  lined  with  fire-brick;  the  diame- 
ter of  the  shell  being  proportionately  increased. 

The  baby-cupola  shown  is  one  which  experimenters 
and  college  instructors  could  well  use  for  giving  in- 
structions in  melting,  and  will  be  of  value  for  scientific 
research  in  all  cases  where  the  melting  of  small 
iron  will  answer  all  practical  purposes. 

Horizontal  chill-mould,  and  the  specimen  obtained 
therefrom  for  testing  contraction  or  chill,  is  seen  in  Fig. 
114,  page  506.  Two  sizes  of  these  pig-moulds  can  be 
used,  or  only  one,  as  the  furnaceman  may  deem  best,  in 
following  out  experiments  and  tests,  as  described  later 
on.  Fig.i  15  shows  cross-sections  through  the  middle  of 
the  respective  iron  moulds;  and  the  larger  cross-sec- 
tion shows  also  the  tapering-rule,  D,  applied  at  the 
end  of  the  mould,  to  measure  contraction.  It  will  be 
noticed  that  the  thickness  'of  these  miniature  pig 
moulds  or  chills  is  one  inch.  Any  variation  from 
this  thickness  would  affect  the  depth  of  the  chill.  It 
is,  therefore,  necessary  that  care  should  be  exercised  to 
have  always  the  same  thickness  in  any  standard  chill 
pig-mould  which  might  be  adopted,  that  did  not  ex- 
ceed two  inches  thick.  The  author  does  not  wish  to 
be  understood  as  advising  records  to  be  taken  of  the 
chill  from  the  test-specimens,  in  cases  where  very  fine 
results  are  desired,  unless  note  be  taken  of  the  fluidity 
of  the  metal  at  the  moment  the  chill  specimens  are 
poured.  This  is  done  in  the  author's  system  by  means 
of  fluidity  strips  attached  to  test  bars,  as  at  S,  in  Figs. 
113  and  121,  and  also  in  Fig.  122,  pages  503,  509  and  514. 

In  Fig.  1 2 1  a  chill  piece  will  be  seen  at  B,  which  is 
the  same  as  shown  at  A,  Fig.  120,  and  which  is  a  form 


FIG.  113. 


J 4 

O 


O 


FIG.    112. 


504  METALLURGY    OF    CAST    IRON. 

of  chill  used  with  the  test  bars  shown,  and  is  three- 
eighths  inch  thick  by  three  inches  long,  and  made  of  soft 
steel.  Only  one  side  or  half  of  the  test  bar  is  here 
considered  in  measuring  a  chill  for  record.  For  iron 
above  1.25  per  cent,  silicon  and  no  higher  than  0.03 
per  cent,  in  sulphur,  this  system  of  obtaining  chill- 
records  indicated  in  Fig.  121,  will  work  very  satis- 
factorily. For  iron  lower  in  silicon  or  higher  in  sul- 
phur, it  may  be  often  necessary  to  have  a  larger  body 
of  iron,  in  order  to  prevent  a  specimen  being  chilled 
all  the  way  through.  In  such  cases,  chill-blocks,  as 
shown  in  Figs.  114,  115,  and  116,  maybe  required  to 
obtain  chill  records.  Where  best  value  is  to  be  attrib- 
uted to  the  chill  records,  the  fluidity  should  be  noted  to 
be  the  same  by  eye  or  by  the  means  shown  in  Fig.  121. 

Fig.  116  shows  a  longitudinal  section  through  the 
chill  pig-mould  of  Fig.  114.  The  well  at  B  is  provided 
to  prevent  cutting  the  chill  in  pouring,  and  to  cause 
the  bar  to  pull  towards  one  end  in  contracting,  so  as  to 
permit  the  contraction  to  be  readily  measured  by 
means  of  the  tapering  rule,  shown  at  D.  This  test 
specimen,  being  twelve  inches  long,  provides  a  con- 
venient length  for  measuring  the  contraction,  and  can 
also  be  readily  broken  to  note  its  fracture,  or  can  be 
drilled  to  obtain  samples  for  analysis. 

The  sections  in  Fig.  115  show  that  the  bottom  sur- 
face of  the  chill-mould  is  round,  possessing  no  corners 
to  cause  any  one  part  of  the  specimen  to  be  chilled 
deeper  than  another,  thereby  causing  internal  strains 
and  preventing  natural  contraction  of  the  iron,  owing 
to  one  part  of  the  specimen  being  thrown  into  higher 
combined  carbon  than  another.  This  consideration, 
the  author  believes,  will  cause  any  one  making  a 


PHYSICAL    TESTS    FOR    THE    BLAST-FURNACE,     ETC.      505 

study  of  the  subject  to  agree  with  him  in  advocating 
the  principle  .of  the  round  chill. 

The  tapering  rule  D,  Figs.  115  and  116,  is  graduated 
on  one  side,  as  shown,  to  measure  the  contraction  in 
the  sixty-fourths  of  an  inch.  The  rule  is  cut  off  on 
the  small  end  at  a  point  where  it  is  one-sixteenth  of 
an  inch  in  thickness.  From  this  the  taper  runs  up 
two  inches,  at  which  point  it  measures  three-six- 
teenths of  an  inch.  The  distance  between  the  one- 
sixteenth  and  three-sixteenths  points  is  then  equally 
divided  by  six  lines,  as  shown,  so  as  to  read  to  the  one- 
sixty-fourth  part  of  an  inch,  according  as  the  space  of 
contraction  will  permit  the  rule  to  be  inserted  between 
the  chill-mould  and  the  pig  specimen,  as  shown.  The 
lines  being  one-quarter  of  an  inch  apart,  the  scale  can 
be  easily  read;  but  the  rule  could,  of  course,  be  grad- 
uated finer  if  desired. 

The  study  of  the  element  of  contraction,  as  it  can 
be  defined  from  any  pig  specimens,  Figs.  114,  115  and 
1 1 6,  will  prove  very  valuable,  and,  in  time,  may  enable 
a  tester  to  know  at  a  glance,  without  further  research, 
the  true  "  grade  "  of  an  iron.  It  can  aid  the  furnace- 
man  to  detect  deception,  which  is  now  known  to 
exist  in  the  fracture  of  ' '  direct  metal, ' '  and  also  to 
learn  the  true  effects  of  re-melting  iron,  and  what 
metalloids  cause  the  greatest  contraction  in  the  iron. 
At  E,  in  Figs.  1 14  and  1 1 6,  will  be  seen  a  depression 
of  about  one-quarter  of  an  inch  below  the  top  surface 
of  the  chill -mould.  This  is  to  provide  means  for  a 
"  flow-off,"  to  insure  the  chill  specimens  being  always 
of  the  same  thickness  and  prevent  any  iron  running 
over  the  edges  of  the  mould  to  retard  free  contraction 
in  any  manner.  The  chill-mould,  of  course,  is  set  level. 


FIG.  114.— CHILL    PIG    MOULD    AND    CASTING. 


FIG.  115.— CROSS   SECTION   OF   SMALL   AND    LARGE   CHILL   PIG   MOULDS. 


FIG.  1 1 6. —LONGITUDINAL   SECTION   OF   CHILL   PIG   MOULD. 


PHYSICAL    TESTS    FOR    THE    BLAST-FURNACE,     ETC.      507 

By  using  together  the  chill-moulds  of  both  sizes,  as 
shown  in  Fig.  115,  an  excellent  illustration  will  be 
afforded  of  the  reasons  why  many  castings  crack  or 
pull  apart,  owing  to  the  work  being  badly  propor- 


FIG.  II?.— MOULD    READY   FOR    CASTING. 


FIG.  1 1 8.— FLASK    AND    PATTERN. 


tioned.  The  small  pig  test  specimen  will  always  show 
a  greater  contraction  than  the  large  one.  Such  ill  re- 
sults in  cracks,  etc.,  are  often  placed  on  the  furnace- 
man's  shoulders  by  claiming  that  he  had  sent  "  bad 
iron."  Should  a  furnace-man  not  care  to  use  these 


508  METALLURGY    OF    CAST    IRON. 

two  sizes  of  chill-moulds  at  one  time,  he  may,  under 
proper  conditions,  adopt  either  for  constant  use.  In 
the  case  of  very  low  grades  of  iron  it  might  be  neces- 
sary to  adopt  the- 'larger  chill-mould,  since  in  the 
smaller  one  the  iron  might  ' '  go  all  white. ' ' 

In  moulding  test-bars  for  determining  transverse  or 
tensile  strength  or  the  deflection  or  stretch  of  an  iron, 
the  author  has  advised  a  very  simple  design  of  a  flask 
and  one  which  would  not  require  a  $4-per-day  moulder 
to  make  the  mould.  Any  intelligent  laborer  can  be 
taught  in  a  very  little  while  how  to  mould  and  cast 
such  bars  successfully;  and  this  can  be  easily  done 
in  about  two  minutes. 

In  starting  to  mould  a  single  test  bar,  the  round  test 
bar  pattern,  L,  and  the  fluidity-strip  pattern,  U,  Fig. 

1 1 8,  are  laid  in  the  recesses  of  the  mould  board,  Fig. 

119,  which  has  previously  been  solidly  placed.     The 
half-flask,    H,    Fig.    118,    is   then    laid    on    the    mould 
board,    rammed   up    and    rolled    over,    and    then    the 
"cope*'  is  put  on;  clamps,   at  K,  Figs.    117  and  120, 
having  been  put  on  to  hold  the  two  parts  close  together 
while  the  cope  is  being   rammed  up.     Before  lifting 
the  cope,  the  test  bar   pattern    L  is  pulled  out  end- 
wise.    The  cope  is   now  lifted  off;  the    fluidity-strip 
pattern,    U,    is   drawn   out;    the  cope  is  put  on  and 
clamped;  and  the  mould  is  up-ended  ready  for  casting, 
as  seen  in  Fig.  117.     The  iron  cup,  A,  Fig.  117,  is  used 
for  the  purpose  of  providing  a  wide  funnel  to  pour  into 
and  keep  the  dirt  from  passing  down  with  the  iron. 
The  slot  cut  in  the  iron  end  of  the  flask,  as  seen  at  E, 
Figs.  1 1 7  and  121.,  is  to  prevent  the  iron,  as  the  mould 
fills  up,  from  rising  high  enough  to  touch  the  under 
side   of  the   cup.     Should   the    metal   in   coming   up 


PHYSICAL    TESTS    FOR    THE    BLAST-FURNACE, 


quickly,  as  it  does,  strike  the  under  part  of  this 
an  explosion  could  occur,  making  the  iron  fly  in  all 
directions.  By  the  plan  devised  such  accidents  are 
prevented. 


FIG.  IIQ.— PLAN   OF   MOULD    BOARD. 


FIG.  1 2O,— CLAMP,    CHILL   AND 
MICROMETER. 


FIG.  121. -SECTION    OF   MOULD. 


In  cases  where  the  fluidity  and  chill  tests  are  not  de- 
sired, and  a  plain  round  test  bar  only  is  wanted  (which, 
for  general  purposes,  will  serve  many  ends),  a  plain 
round  pattern,  as  at  L,  Fig.  118,  page  507,  which  in  the 


510  METALLURGY    OF    CAST    IRON. 

rough  is  one  and  one-eighth  inches  in  diam.,  or,  in  fine 
figures,  i .  1 284  inches,  is  all  that  is  required.  (Plans  for 
casting  plain  bars  are  seen  on  pages  521  and  527.)  It  is 
well  to  have  the  lower  end  of  this  pattern  made  a  little 
pointed  for  about  three-fourths  of  an  inch  of  its 
length,  so  as  not  to  give  a  flat  sand  surface  for  iron  to 
drop  on,  as  in  the  case  where  the  bar  is  entirely 
square  on  the  end.  In  making  this  strictly  plain, 
straight,  round  bar,  the  "  cope  "  need  not  be  lifted  off, 
as  the  pattern  can  be  pulled  out  endwise  and  the  flask 
immediately  up-ended,  ready  for  casting  (as  seen  on 
page  507),  in  less  time  than  it  takes  to  tell  it. 

Some  might  think  a  pattern  rammed  up  on  end  in  a 
wooden  box  (see  page  527)  would  answer  just  as  well. 
To  do  this  and  not  have  any  swells  on  the  bar  requires 
considerable  care  in  ramming  the  mould.  By  the  plan 
here  presented,  ho  more  time  is  required,  and  there  is 
more  assurance  of  unskilled  labor  obtaining  a  perfect, 
even,  true  round  bar,  free  of  all  swells  for  its  entire 
length,  and  without  a  joint  mark  on  it.  These  are 
essential  requirements  for  a  test  bar. 

Should  it  be  desired  to  cast  only  plain  bars,  without 
the  attached  fluidity-strips,  the  hole  in  the  end  of  the 
flask,  as  at  N,  Fig.  121,  could  be  placed  in  the  center 
of  the  flask  instead  of  where  it  is  shown  in  the  figure. 

Fig.  112,  page  503,  gives  all  the  dimensions  of  the 
single  test  bar  flask  shown  in  Figs.  117  and  118.  Fig. 
113  shows  a  single  bar  with  its  fluidity-strip  S,  as  taken 
from  a  mould.  The  two  projections  shown  on  the  bai- 
rn this  figure,  also  at  A  and  M,  Fig.  103,  page  482,  con- 
stitute plans  to  be  utilized  to  measure  the  contraction 
of  such  bars  when  they  are  moulded  in  jointed  flask. 

The  simultaneous  casting  of  duplicate  test  bars,  illus- 


PHYSICAL    TESTS    FOR    THE    BLAST-FURNACE,     ETC.      $11 

trated  in  the  next  Chapter,  shows  the  design  of  flask, 
mould  board  and  patterns,  with  the  improved  "  whirl 
gate,"  which  the  author  designed  in  the  year  1895  for 
"  running  "  round  bars  cast  on  end.  The  method  com- 
plete is  one  which  the  testing  committee  of  the  West- 
ern Foundrymen's  Association  has  used  with  the 
greatest  success  in  obtaining  perfectly  solid  bars.  As 
furnacemen  advance  in  the  work  of  physical  tests, 
many  may  desire  to  take  up  questions  which  the  single 
cast  bar  will  not  permit  of  investigation,  requiring  bars 
cast  double,  plans  for  which  are  cited  in  the  next 
Chapter.  Whether  the  exact  plans  presented  in  this 
paper  be  adopted  or  not,  the  principles  upon  which 
they  are  based  cannot  be  ignored  in  the  attempt  to 
secure  true  physical  tests  at  the  furnace  or  foundry. 

As  a  supplement  to  this  Chapter,  the  author  desires 
to  again  call  attention  to  the  importance  of  the  adoption 
by  the  engineering  and  foundry  world  of  test  bars  of  a 
size  that  can  establish  a  fair  relation  to  the  chemical 
analysis  of  iron,  or  accord  with  the  commercial  value 
which  usage  has  given  to  degrees  in  its  strength.  By 
a  study  of  Chapter  LXIX.,  page  528,  it  will  be  seen 
that  we  should  riot  use  a  bar  smaller  than  of  one  square 
inch  area.*  A  few  are  still  adhering  to  the  use  of  one- 
half  inch  square  bars,  claiming  that  they  have  value  in 
giving  a ' '  sensitive  test. ' '  I  would  ask  such,  after  having 
studied  pages  454,  467  and  484,  if  they  have  not  drawn 
the  wrong  conclusions,  or  if  this  does  not  truly  mean 
that  bars  as  small  as  one-half  inch  square  or  round  are 
so  "  sensitive  "  to  variations  in  the  "temper  "  or  damp- 
ness of  sands  and  degrees  in  fluidity  of  metal,  as  to 
make  them  very  erratic,  and  hence  valueless  to  be  used 
for  a  comparative  test  in  any  one  single  grade  of  iron, 
to  say  nothing  about  their  inability  to  denote  degrees  of 
strength  in  the  various  grades  used  in  general  founding. 

*The  American  Foundrymen's  Association  recommends  that 
bars  should  not  be  smaller  than  one  and  one-half  inches  diameter- 
See  pages 487  to  573. 


CHAPTER  LXVII. 

DESIGN  OF  APPLIANCES  AND  METHODS 

FOR  CASTING    ROUND  TEST 

BARS    ON    END. 

To  successfully  cast  round  test  bars  on  end,  when 
the  contraction  or  fluidity  is  required  in  connection 
with  the  strength  and  chill  of  iron,  it  is  essential  to 
utilize  a  flask,  etc. ,  designed  especially  for  such  work. 
Figures  122,  123,  and  124,  pages  514  to  516,  illustrate 
the  design  of  flask,  mould  board  and  patterns  with 
the  "  whirl-gate  "  which  the  author  has  designed  for 
such  a  purpose.  The  test  bar  patterns  and  runner  are 
illustrated  at  H,  H,  and  F,  Fig.  128,  page  524.  These 
patterns  are  also  seen  at  D  D  and  A,  Fig.  122,  page  514. 
The  plan  of  drawing  the  patterns  out  endwise  as  shown 
avoids  the  necessity  of  any  rapping  of  patterns ;  hence, 
if  the  mould  is  fairly  rammed  and  the  pins  of  the  flasks 
fit  true,  it  will  be  evident  that  few,  if  any,  joints  will 
be  seen  on  the  bars  obtained. 

Moulds  cast  on  end  from  a  parallel  pattern  will  al- 
ways be  largest  at  the  bottom,  owing  to  the  head  press- 
ure. In  making  the  test  bars  patterns  D  D,  Fig.  122, 
for  the  first  standard  mentioned  in  Chapter  LXIX. ,  as 
an  illustration,  have  them  1.1284  inches  in  diameter, 
at  one  end.  and  1.0884  at  the  other.  In  common 


DESIGN    OF    TEST    BAR    APPLIANCES,    ETC.  513 

figures  these  would  measure  one  and  one-eighth 
inches  diameter  at  the  large  end,  and  one  and  three- 
thirty-seconds  of  an  inch  at  the  small  end,  and  of  the 
same  length  seen  in  Fig.  122.  By  having  a  ring  at  the 
large  end,  as  seen  at  H,  Figs.  122  and  128,  the  smaller 
end  will  always  be  the  down  one  in  moulding,  and  in 
ramming  the  mould,  do  so  to  such  a  degree  of  hard- 
ness as  to  permit  sufficient  straining,  due  to  head  press- 
ure, to  have  the  castings  come  out  closely  alike  as  to 
size  at  the  bottom  and  top. 

It  is  well  to  mention  at  this  point  that  should  any 
desire  to  make  their  test  bars  in  a  "  dry-sand  "  mould, 
they  can  readily  do  so,  as  there  is  no  wood  whatsoever 
connected  with  the  flasks,  thus  making  it  practical  to 
place  the  mould  in  an  oven  to  be  dried.  For  mallea- 
ble and  steel  testing  and  some  special  purposes  in  iron, 
a  "  dry-sand  "  mould  might  often  be  found  a  very  good 
method  to  adopt. 

Referring  to  the  question  of  "  chilling,"  it  cannot  but 
be  readily  seen  that  as  arranged  by  this  system,  the  test 
bar  and  the  chill  must  remain  in  close  contact  until  re- 
moved by  hand,  hence  truly  recording  the  full  chill- 
ing qualities  of  the  iron.  At  V  V,  Fig.  126,  page  522, 
can  be  seen  the  chill  used  in  this  system.  It  is  simply 
two  half-circles  three  inches  long  by  three-eighths  of 
an  inch  thick,  having  a  hole  drilled  in  them  to  fit  over 
the  pattern  tips  W  W,  Fig.  122,  These  chills  are  set 
on  over  the  pattern  before  starting  to  fill  the  nowel 
with  sand,  and  in  shaking  out,  must,  of  course,  be 
picked  up  and  used  as  long  as  they  last.  They  are 
made  of  a  soft  steel  shaft,  -which,  after  being  drilled 
or  bored  out,  are  then  split  as  seen.  See  page  502. 

In  the  case  of  very  hard  grades  of  iron,  such  as 


514 


"METALLURGY    OF    CAST    IRON. 


would  go  "  white  "  in  the  one  and  one-eighth  round 
test  bar  at  the  chill  end,  when  a  chill  was  placed  on 
the  pattern  in  ramming  the  mould  which  embraces 
such  iron  as  is  used  in  car  wheel,  chill  roll,  and  gun 
metal — the  author  would  advise  the  adoption  of  the 


FIG.  122.— WHIRL-GATE,    TEST   BAR    PATTERNS   AND   CASTING. 

second  or  third  standard  bars  of  one  and  five-eighths 
inches  and  one  and  fifteen-sixteenths  inches  in  diame- 
ter described  in  Chapter  LXIX.  If  the  chill  goes  all 
"  white  "  in  the  largest  bar,  he  would  use  the  largest 
chill  block  mould  seen  in  Fig.  115,  page  506,  as  a 


DESIGN    OF    TEST    BAR    APPLIANCES,     ETC. 


515 


standard.  To  find  the  depth  of  a  chill  with  either  of 
these  round  test  bars,  hold  the  chill  end  (after  a  bar 
has  been  tested)  over  a  solid  piece  of  iron  and  strike  it 
as  seen  in  Fig.  125,  page  522.  A  notch  being  cast  in  the 
chill  end  opposite  the  chill  side,  as  seen  at  X,  Fig.  103, 
page  482,  permits  the  bar  being  readily  broken  when 
held  as  above  described.  To  measure  the  depth  of  a 
1 '  chill, ' '  consider  only  that  portion  turned  ' '  white  ' ' 


FIG.     123. — NOWEL    HALF    OF   FLASK. 

and  the  depth  it  has  been  chilled  is  to  be  defined  by 
the  eye.* 

Knowing  that  the  degree  of  fluidity  has  an  effect  and 
should,  for  close,  fine  work  be  recorded  in  order  to 
make  intelligent  comparisons,  the  author  has,  in  combi- 
nation with  other  new  features  of  this  system,  provided 
at  U  U  and  VS  S,  Fig.  122,  an  arrangement  made  pos- 
sible with  this,  system,  by  which  we  can  measure  the 

*  A  plan  to  take  blue  prints,  etc.   of  chills  is  seen  on  page  588. 


METALLURGY    OF    CAST    IRON. 

height  metal  will  rise  in  a  long,  thin  wedge.  These 
fluidity  and  life  measuring  strips  are  ten  inches  long 
by  three-fourths  of  an  inch  wide,  as  at  S,  in  Fig.  121, 
page  509.  The  base  of  these  strips  measures  one-eighth 
of  an  inch  thick,  and  they  run  up  to  a  knife  edge  at 
the  top.  They  are  a  very  sensitive  thermometer  to  de- 
note both  the  fluidity  and  life  of  metal,  as  will  be 
found  by  any  one  adopting  the  system.  Having  the 
fluidity  strips  poured  in  a  vertical  position,  as  arranged 
in  this  system  in  connection  with  the  heavier  bodies, 


FIG.    124. — MOULD   BOARD,  BOTTOM   PLATE   AND    COPE   HALF   OF   FLASK. 

prohibits  any  forced  or  unnatural  pressure  to  be  ex- 
erted, so  as  to  have  the  strips  falsely  record  the 
fluidity  of  metal  when  bars  are  poured.  The  metal 
cannot  rise  in  the  fluidity  strips  any  faster  than  in  the 
test  bar,  and  hence  the  strips  must  have  a  gradual 
rise.  Their  measurement  can  be  accepted  as  practical 
and  representing  the  true  fluidity  and  life  of  metal 
at  the  time  it  is  poured.  Take  such  fluidity  strips 
and  cast  them  flat  (See  Fig.  71,  page  375);  the  length 
they  "  run  ' '  are  largely  determined  by  the  way  they  are 


DESIGN    OF    TEST    BAR    APPLIANCES,     ETC.  517 

poured.  Unless  great  care  is  used,  one  may  be  able  to 
make  them  "run"  fully  four  inches  farther  than  if  they 
were  poured  steadily,  whereas,  when  poured  vertically, 
as  in  the  author's  system,  if  there  is  a  quick  dash  at 
any  time  it  cannot  raise  the  metal  in  the  fluidity  strips 
any  faster  than  in  the  test  bar  moulds,  thereby  causing 
a  natural  and  equal  rise  to  truly  denote  the  metal's 
fluidity  or  life  at  the  moment  the  bars  are  poured. 

To  obtain  the  contraction  of  a  bar,  the  distance  be- 
tween the  points  or  tips  V  V,  Fig.  122,  page  514,  is 
measured.  These  contraction  tips  are  accurately  cast 
in  the  mould  by  means  of  four  projections  forming  part 
of  the  flask,  two  of  which  are  seen  at  B  B,  Fig.  123, 
These  projections  "  chill  "  one  face  of  the  contraction 
tips  V  V,  thereby  giving  a  clean  face  to  measure  from. 
The  lower  tips  are  given  form  by  reason  of  a  swell 
being  made  at  the  base  of  the  fluidity  strips,  as  will  be 
seen  at  the  lower  V  in  Fig.  122.  The  upper  tips  are 
formed  by  having  loose  tip  patterns  placed  in  the  re- 
cesses of  the  mould  board  as  seen,  in  such  a  manner 
that  the  uppermost  projection  B  of  the  flask  is  on  the 
top  side  of  the  tip  V.  By  this  arrangement  full  free- 
dom for  expansion  at  the  moment  of  solidification  is 
permitted,  as  when  this  takes  place  it  can  extend  its 
length  downward  in  the  sand  forming  the  bottom  of 
the  mould.  These  contraction  tips  are  cast  twelve 
inches  apart  and  will  be  found  as  arranged  to  provide 
positive  points  for  obtaining  the  contraction  of  any 
'  *  grade  ' '  of  iron. 

At  A,  Fig.  122,  js  seen  the  pattern  used  for  forming 
the  pouring  basin  and  runner  which  leads  to  the 
"  whirl-gate."  At  N  is  shown  how  the  pouring  basin 
and  runner  look  before  being  broken  from  the  test 


518  "METALLURGY  OF  CAST  IRON. 

bars.  The  reason  for  the  recess  seen  in  the  end  of 
the  flask  at  E,  Fig.  123,  is  to  prevent  the  metal  rising 
above  that  height  at  the  close  of  pouring,  and  thus  not 
give  the  metal  a  chance  to  form  a  "  fin  "  between 
the  top  joint  of  the  flask  or  over  the  top  of  its  ends  at 
H  and  thus  still  the  more  positively  insure  the  casting's 
own  weight  pulling  the  contraction  downward  in- 
stead of  the  contraction  pulling  the  whole  body  of  the 
casting  upward  from  the  bottom  of  the  moiild,  a  fac- 
tor which  has  been  the  cause  of  pulling  the  neck  off 
from  rolls  or  causing  checks  or  total  separation  of  parts 
in  other  kinds  of  castings.  The  cross  bar  in  the  flask 
is  formed,  as  seen  at  R,  Fig.  123,  for  the  purpose  of 
fitting  over  the  runner  where  it  connects  with  the 
whirl-gate's  basin,  to  assist  the  same  end  just  men- 
tioned in  compelling  the  contraction  to  follow  a 
natural  tendency,  and  not  lifting  the  whole  weight  of 
a  casting  upward,  as  previously  explained.  At  R  R 
and  O  O,  Fig.  122,  are  seen  male  and  female  pins  and 
holes,  which  are  arranged  as  shown  so  as  to  insure  these 
two  sections  of  the  patterns  coming  together  at  true 
points,  to  make  it  impossible  for  the  action  of  the  ram- 
mer to  distort  them  in  any  way. 

jl  In  making  the  «•  whirl-gates"  seen  at  T,  Fig.  122, 
the  operator  must  so  proportion  them  that  the  runner 
joined  to  the  basin  A,  Fig.  122,  can  carry  the  iron  to 
the  inlet  of  the  "  whirl-gates  "  as  fast  as  they  can  de- 
liver the  metal  to  the  motild,  the  idea  being  that  as 
soon  as  the  pouring  is  commenced,  with  either  of  the 
three  standards,  the  upright  runners  are  so  propor- 
tioned that  the  pouring  basin  N  can  be  kept  full  of  iron, 
to  prevent  any  dirt  passing  down  the  runner  through 
the  "  whirl-gates  "  to  the  mould.  Owing  to  the  small 


DESIGN    OF    TEST    BAR    APPLIANCES,    ETC.  519 

diameter  of  the  one  and  one-eighth  inch  test  bar,  when 
this  size  bar  is  used,  care  must  be  taken  in  getting  a 
good  form  to  the  "  whirl-gate. "  If  that  form  shown 
in  the  cut  at  T,  Fig.  122,  is  closely  followed,  it  will  be 
found  to  give  an  excellent  whirl  to  the  metal  as  it  rises 
in  the  mould,  so  as  to  bring  any  dirt  that  may  by 
chance  flow  with  the  metal  into  the  mould  up  to  the 
top  of  the  casting,  and  thus  cause  all  test  bars  to  be  of 
a  sound  fracture  when  broken.  The  "whirl-gate" 
portion  of  the  pattern  seen  on  the  left  of  Fig.  122  is 
made  of  brass  or  babbitt  metal.  The  fluidity  strips 
UU  are  cast  in  the  main  patterns  after  they  are  fin- 
ished to  the  proper  size.  These  fluidity  strips  can  be 
made  of  any  thin  piece  of  wrought  iron  or  steel.  To 
strengthen  the  union  of  the  "  whirl-gate  ' '  portion  of 
the  pattern  with  the  body  of  the  test  bars,  brass  or 
copper  wire  is  laid  in  the  mould  and  "  cast  in. "  The 
size  of  the  "  whirl-gate  "  where  it  joins  the  one  and 
one-eighth  inch  diameter  bar  is  about  one-eighth  inch 
in  thickness  by  one  inch  wide.  For  the  one  and  five- 
eighths  inch,  one  and  fifteen-sixteenths  inches  diame- 
ter bars,  make  this  part  of  the  gate  one  and  one-quar- 
ter inches  and  one  and  one-half  inches  wide  respect- 
ively, maintaining  the  same  thickness  of  one-eighth 
inch  as  above  shown  in  the  one  and  one-eighth  inch 
diameter  bar. 

It  will  be  noticed  that  iron-perforated  bottom-plates 
are  used  instead  of  wooden  bottom  boards  to  give  a 
backing  to  the  "  cope  "  and  "  nowel  "  when  up-ended 
in  order  to  prevent  the  pressure  of  the  metal  from 
bursting  the  mould  when  cast  at  such  points.  To  se- 
cure these  iron  bottom  plates  in  place  rapidly,  strips  of 
iron  are  pivoted  at  F  F,  Fig.  124,  on  the  main  part  of 


520  METALLURGY    OF    CAST    IRON. 

the  flask  as  seen,  then,  by  having  a  tapering  projection 
cast  on  the  bottom  plates,  as  seen  at  X,  Fig.  124,  a  few 
taps  of  a  hammer  on  the  binding  strips  F  F  are  all 
that  is  necessary  to  secure  the  bottom  plate  in  place. 

Specifications  often  call  for  tests  from  turned  bars. 
The  author  has  arranged  for  such  a  test  in  a  very 
simple  manner,  requiring  but  little  machine  work. 
At  T,  Fig.  127,  page  522,  is  shown  a  bar  having  a 
swell  cast  on  it.  This  can  be  made  from  six  inches  to 
eight  inches  long  and  of  the  diameter  necessary  to 
cause  the  '  *  grade  ' '  of  iron  used  to  be  readily  ma- 
chined to  1.128  inches,  1.596  inches  or  1.955  inches 
diameter,  so  as  to  equal  a  one,  two  or  three  square 
inch  area  section  and  conform  with  the  diameter  of 
the  rough  bars  given  above  for  unfinished  testing. 
The  harder  the  grade  of  iron  the  larger  diameter 
necessary  at  T  to  lessen  the  influence  to  chill  or  cause 
metal  to  be  too  hard  for  turning.  But  this  should  not 
exceed  one  and  five-eighths  inches  diameter  with  the 
one  and  one-eighth  inches  diameter  bar.  Any  iron 
that  will  be  found  too  hard  to  be  machined  in  this 
diameter  of  one  and  five-eighths  inches  of  a  swell,  the 
second  size  or  third  size  of  a  standard  bar  could  then 
be  utilized  in  having  a  swell  cast  on,  half  an  inch 
larger  in  diameter  than  plain  rough  bars  called  for. 
Whatever  size  of  a  swell  is  used,  the  same  should  be 
constantly  used,  in  order  to  always  have  the  same 
amount  of  stock  to  be  turned  off  a  test  specimen. 
There  are  very  few  grades  of  iron  which  can  not  be 
machined  from  a  body  one  and  five-eighths  inches 
diameter.  The  author  has  had  bars  with  a  swell  of 
one  and  five-eighths  inches  diameter,  cast  on  one  and 
one-eighth  inch  bars  with  grades  of  iron  used  in  mak- 


DESIGN    OF    TEST    BAR    APPLIANCES,     ETC.  52 1 

ing"  chill  rolls,  car  wheels  and  gun  metal,  and  found  no 
difficulty  in  having  them  machined,  as  shown  by  the 
turned  bars  given  with  the  cuts  seen  on  page  472. 
The  plan  adopted  to  form  these  swells  is  simply  to 
place  half  sections  of  patterns,  as  seen  at  N  N,  Fig. 
126,  over  the  regular  test  bar  pattern  when  moulding 
them ;  then  when  the  cope  is  lifted  off,  they  are  drawn 
separately  from  the  mould.  Of  course,  bars  can  be  cast 
plain  their  full  length  and  then  have  a  recess  about 
three  inches  long  turned  into  them,  instead  of  follow- 
ing the  swell  plan,  wherever  this  is  preferable. 

The  flask's  dimensions  for  casting  iJ/&  inch  round 
bars,  as  seen  in  Figs.  123  and  124,  are  to  be  made 
eight  and  one-half  inches  by  17  inches  inside  measure- 
ments and  four  inches  deep.  To  cast  two,  one  and 
five-eighths  inches  or  one  and  fifteen-sixteenths  inches 
test  bars,  for  the  second  and  third  standard,  mentioned 
page  533,  the  only  change  necessary  in  the  whole 
system  is  to  make  the  flask  ten  inches  to  eleven  inches 
wide  on  the  inside.  If  desirable,  one  flask  could  be 
made  to  answer  for  moulding  either  the  one  and  one- 
eighth  inch,  one  and  five-eighths  inch  or  one  and 
fifteen -sixteenths  inch  diameter  bars,  simply  by  hav- 
ing a  flask  1 1  inches  wide  and  the  holes  in  the  end  of 
the  flask  at  H,  Figs.  123  and  124,  made  one  and 
fifteen -sixteenths  inch  diameter,  also  the  one  and  one- 
eighth  inch  or  one  and  five-eighths  inch  test  bar  pat- 
terns to  have  a  swell  of  one  and  fifteen-sixteenths 
inches  diameter  at  the  point  where  it  would  rest,  or 
fill  the  hole  H  when  the  bars  are  being  moulded. 

When  the  strength  only  is  desired,  then  bars  can  be 
moulded  in  any  common  jointless  flasks  for  the  length 
of  the  bars  or  by  *'  bedding  "  them  in  the  floor  simply 


522 


METALLURGY    OF    CAST    IRON. 


by  standing-  patterns  on  their  end  to  ram  them  up  on 
the  plan  illustrated  on  page  527.  In  gating  and  pour- 
ing such  bars  the  metal  is  best  dropped  from  the 
top  through  a  cope,  and  not  allow  it  to  strike  the 
sides  of  the  mould,  and  when  two  or  more  bars  are 
moulded  in  one  flask,  their  top  pouring  "gates" 
should  be  all  con- 
nected  to  one 
pouring  basin, 
made  deep  enough 
so  as  to  keep  the 
"gates"  full  of 
metal  when  the 
bars  are  being  poured.  By  careful  work,  plain  bars  can 


r  r 
in 


FIG.    126. 


be  cast  on  end  by  this  plan  that 
will  prove  sound  when  broken. 
Plans  for  single  bars  are  described, 
page  509,  and  plans  for  two  or 
more  plain  bars  being  cast  to- 
gether are  seen  in  Fig.  129,  page  527. 

Let  it  ever  be  remembered  that, 
at  the  best,  a  test  bar  can  only  be 
used  to  make  relative  comparisons 
in  the  physical  qualities  of  mixtures, 
and  to  properly  secure  these  a  size 
and  form  of  a  bar  must  be  used  that 
is  not  sensitively  affected  by  the 
dampness  of  a  green  sand  mould, 
and  degrees  in  fluidity  of  metal. 
This  demands  that  a  bar  be  of  round 
form,  not  less  than  one  and  one-eighth  inches  in  diam- 
eter, and  that  such  is  best  cast  on  end,  as  is  displayed 
by  reading  Chapters  LVL,  LIX.  and  LXV. 


FIG.   127. 


CHAPTER  LXVIII. 

MOULDING,   SWABBING  AND  POURING 
TEST  BARS. 

In  moulding  test  bars,  every  precaution  should  be 
taken  to  insure  a  uniform  treatment  at  all  times.  The 
sand  should  always  be  of  the  same  ' '  temper, ' '  as  far 
as  practical,  rammed  regularly,  and  of  the  same 
degree  of  hardness.  The  best  way  to  attain  this  is  to 
select  some  one  intelligent  man,  who  will  make  it  his 
business  to  do  all  the  moulding  and  casting  of  test  bars 
which  shall  be  required  for  any  one  department.  The 
end  to  be  sought  in  obtaining  test  bars  is  that  they 
should  be  as  near  as  possible  the  size  of  the  pattern 
from  which  they  are  moulded.  There  are  two  factors 
affecting  these  results.  The  first  is  in  the  ramming 
and  ' '  temper ' '  of  sand,  the  second,  in  drawing  the 
patterns.  Practice,  with  some,  is  such  as  to  require 
more  or  less  jarring  or  rapping  of  the  patterns  before 
they  were  removed  from  the  mould,  and  while  one 
moulder  might  not  do  so  to  a  perceptible  degree, 
another  might  go  to  the  extremes.  A  system  to  be 
favored  in  making  comparisons  in  one's  own  shop, 
or  in  the  case  of  one  firm  with  another,  should  be 
arranged  so  as  to  remove  any  semblance  of  the  ne- 
cessity of  rapping  or  jarring  patterns.  For  moulding 
test  bars,  some  space  as  near  the  cupola  as  practical 


524 


METALLURGY    OF    CAST    IRON. 


should  be  devoted  for  this  special  work  and  there 
should  be  a  place  for  every  tool  and  all  kept  as  neat 
and  clean  as  possible. 

After  a  mould  has  been  rammed  up,  by  the  author's 
system,  the  round  portion  of  the  test  bar  pattern  is 
then  pulled  out  endwise,  before  the  cope  is  lifted  off, 
as  seen  in  Fig.  128,  this  page.  For  a  handle  to  draw 
out  the  test  bars  endwise,  two  inches  of  the  patterns 
project  outside  of  the  flask  as  shown  at  H.  The  cope 
is  then  lifted  off  and  the  balance  of  the  pattern  and 
gates  drawn  out. 
After  all  loose  H 

sand  or  dirt  has 
been  blown  out 
lightly  with  a  pair 
of  bellows,  the 
cope  is  closed  on, 
flask  clamped,  and 
then  up-ended 
ready  for  casting, 
as  seen  in  Fig.  130, 
on  page  527. 

In  drawing  out  the  test  bar  patterns  endwise,  give 
them  a  half-twist  around  the  mould  before  starting  to 
pull  the  pattern  straight  out  and  they  will  come  very 
easily,  as  it  only  requires  a  pull  of  from  eight  to 
twelve  pounds  at  the  moment  of  greatest  power  to 
draw  them  out.  The  pattern  should  be  kept  well  var- 
nished or  bees-waxed,  so  as  to  prevent  the  friction  of  the 
sand  wearing  them  away  by  a  few  years'  use  or  cause 
them  to  become  rough,  making  a '  *  dirty  mould. ' '  When 
the  chills  at  A,  Fig.  120,  and  V  V,  Fig.  126,  pages  509 
and  522,  are  used,  care  should  always  be  taken  that  they 


MOULDING,    SWABBING    AND    POURING    TEST    BARS.     525 

are  not  rusty  or  wet  from  any  cause,  as  this  could  cause 
an  explosion  when  pouring  a  mould.  It  is  well  to  rub 
the  chills  with  a  very  slight  coating  of  coal  oil  or  good 
machinery  oil,  where  they  are  not  in  constant  daily  use. 
The  •«  swab  "  is  something  that  should  not  be  used  in 
moulding  test  bars,  if  possible  to  avoid  it,  for  the  rea- 
son that  if  sands  are  made  wetter  in  some  portions  of 
a  mould  than  others,  it  affects  the  grain  of  the  iron  at 
that  place,  making  it  different  from  the  rest,  and  hence 
it  may  be  an  element  likely  to  cause  erratic  results  and 
deception  in  recording  the  iron's  true  strength.  If 
the  sand  is  such  that  a  swab  must  be  used,  it  should 
be  done  with  the  greatest  caution,  especially  at  that 
part  of  the  mould  where  the  bar  will  break  in  being 
tested.  The  plan  of  pulling  the  patterns  out  endwise 
before  the  cope  is  lifted  off,  as  devised  by  the  author 
in  his  system,  makes  it  unnecessary,  with  sand  at  all 
fit  to  mould  test  bars  in,  to  use  any  water  on  the  joint 
of  the  round  part  of  the  bar.  The  swab  might  be  used 
a  little  around  the  gates,  but  it  is  best  to  avoid  it  if 
at  all  possible  to  make  a  clean,  firm  mould  without  do- 
ing so.  Construct  a  swab  so  that  the  flow  of  water  can 
be  under  perfect  control  by  the  lightest  squeeze.  To 
insure  the  stream  or  drops  striking  just  the  part  or 
spot  desired  to  be  dampened,  a  good  plan  is  to  insert  a 
piece  of  one-eighth  inch  wire,  or  long,  thin  nail,  through 
the  body  of  the  swab,  to  project  below  it  about  two 
inches,  as  a  guide  to  direct  the  stream.  By  using  this 
design  of  a  swab,  it  will  be  found  that  only  the  exact 
parts  desired  to  be  dampened  will  be  affected,  and  the 
water  will  not  be  scattered  all  over  the  mould,  making 
parts  like  mud,  as  is  often  done  by  the  kind  of  swabs 
sometimes  used. 


526  METALLURGY    OF    CAST    IRON. 

In  pouring  test  bars,  use  only  "clean  iron. "  Never 
take  iron  having  slag  or  dross  floating  on  top  of  it. 
Not  only  should  the  iron  be  clean,  but  a  "  clean  ladle  " 
should  be  used  and  skimmed  off  before  pouring.  While 
being  poured  it  should  be  skimmed  so  as  to  prevent 
the  oxide,  which  often  rapidly  forms  on  the  surface, 
from  passing  into  the  mould. 

With  the  use  of  round  test  bars  cast  on  end,  an  intel- 
ligent comparison  of  one  class  of  metal  with  another 
will  demonstrate  that  there  is  a  dividing  line  between 
soft  and  hard  grades  as  to  which  would  be  the  strong- 
est with  "  hot  "  or  "dull"  poured  metal.  At  present, 
that  chiefly  concerning  us  here  is,  at  what  tempera- 
ture are  bars  best  to  be  poured.  As  the  founder 
chiefly  makes  'tests  for  comparison,  either  to  test  his 
own  mixtures  or  to  furnish  tests  to  compare  with  those 
of  competitors,  at  the  request  of  a  middle  party,  it 
seems  but  reasonable  and  best  that  a  temperature  be 
maintained  that  would  best  conform  with  that  gen- 
erally used.  I  would  not  advise  a  metal  being  too 
"  hot  "  or  too  "  dull,"  but  something  that  would  aver- 
age about  four  and  one-half  inches  up  in  the  fluidity 
testing  tips  S  and  S,  Figs.  121  and  122,  pages  509  and  5 14. 

Some  founders  might  say  their  iron  was  hotter  and 
would  run  up  higher  to  a  fine  edge  than  that.  I  am 
not  disputing  these,  but  I  do  question  whether  they 
will  always  obtain  the  same  high  fluidity;  and  then 
again  the  iron  may  come  out  of  the  cupola  all  right, 
but  owing  to  some  '  *  hitch  ' '  in  the  moulder  getting 
to  his  "  floor  "  ready  to  pour  at  some  one  time,  could 
throw  them  off  in  their  calculations.  All  elements 
and  conditions  considered,  it  is  decidedly  best  to  pour 
at  a  temperature  while  sure  to  run  and  make  solid  test 


MOULDING,     SWABBING    AND    POURING    TEST    BARS.      527 


bars,  still  not  so  high  but  the  temperature  of  day  in 
and  day  out  can  be  utilized  and  all  delays  allowed 
for,  so  as  to  maintain  a  close  uniformity.  By  endeav- 
oring to  maintain  about  the  same  temperature  when 
pouring,  it  would  go  a  great  way  in  enabling  the  tes- 
ter to  attach  more  value  to  any  comparison  he  might 
wish  to  make  with  his  past  record,  or  with  others. 

The  cut  Fig.  129  is  a  plan  for  casting  plain  test  bars 
on  end,  so  simple  that  any  foundryman  can  find  flasks, 
etc.,  to  instantly  change  from  casting  flat  to  that  of 
casting  on  end,  should  he  desire 
to  do  so.*  E,  E  is  the  test  bar 
mould.  B,  B  are  the  "gates"  con- 
necting the  pouring  basin  and  the 
moulds.  M,  pouring  well.  P, 
cope.  R,  nowel.  For  further  de- 
scription, see  pages  510  and  521. 


FIG.  129.  FIG.  130. 

*A  few  practice  pouring  bars  on  end  without  a  cope,  merely 
dropping  the  metal  directly  into  the  mould,  but  such  a  plan  is 
more  apt  to  give  defective  bars. 


CHAPTER  LXIX. 

UTILITY  OF  THE  TEST  BAR  AND  STAND- 
ARD SYSTEMS  FOR  COMPAR- 
ATIVE   TESTS.* 

Many  lose  sight  of  the  real  utility  of  test  bars.  They 
entertain  the  idea  that  they  will  give  the  actual 
strength,  contraction  or  chill  of  single  or  unduplicated 
castings.  The  only  way  to  obtain  positive  knowledge 
of  these  qualities  is  by  making  test  bars  of  the  same 
thickness  and  form,  if  possible,  as  those  of  the  casting 
for  which  comparisons  were  to  be  drawn.  In  reality 
this  would  mean  making  two  castings  to  be  poured  at 
the  same  time  with  the  same  iron,  and  breaking  one 
to  get  the  strength,  etc. ,  of  the  other.  The  true  utility 
of  the  test  bar  is  simply  comparative,  to  define  differ- 
ences that  may  exist  in  mixtures  of  the  various 
'  *  grades  ' '  of  iron,  or,  in  other  words,  all  that  the  test 
bar  will  do  is  to  denote  the  strength,  etc. ,  of  the  iron 
which  is  poured  into  the  mould ;  and  what  the  shape 
and  size  of  that  mould  would  do  to  distort  the  physical 
qualities  of  the  iron  from  agreeing  with  what  the  test 
bars  have  recorded,  is  largely  left  for  experience  to 
guess  at  or  comparative  tests  of  broken  castings  to 
define. 


*  Revised  paper  presented  by  the  author  to  the  Foundry  men's 
Association,  Philadelphia,  Pa.,  December  2,  1896, 


UTILITY    OF    THE    TEST    BAR,    ETC.  529 

Where  there  are  many  duplicates,  as  in  the  manu- 
facture of  car  wheels,  pipes,  etc. ,  we  can,  by  breaking 
a  few  castings,  and  test  bars  that  have  been  cast  out 
of  the  same  ladle  of  iron,  obtain  a  very  fair  base  as  a 
standard  for  future  comparisons  of  what  may  be  ex- 
pected in  the  castings  themselves  from  test  bars  from 
future  mixtures.  This  is  not  saying  that  single  cast- 
ings made  of  the  same  pattern,  cast  at  different  times, 
could  not  have  any  comparative  knowledge  imparted 
of  their  strength,  etc.,  by  reason  of  using  a  proper  test 
bar,  cast  with  the  same  ladle  of  iron.  If  a  single  cast- 
ing stands  desired  usage  and  the  builder  or  buyer  has 
a  record  of  test  bars  that  was  poured  of  the  same  iron 
with  the  casting,  he  generally  can  rest  fairly  assured 
that,  if  at  any  other  time  he  should  get  another  cast- 
ing made  from  the  same  pattern  with  test  bars  that 
would  show  a  similar  strength,  he  would  have  a  cast- 
ing that  would  be  fairly  equal  in  strength,  etc. ,  to  the 
first  one  made.  And  again,  the  use  of  these  can  often 
prove  protection  to  builders  that  have  machines  broken 
by  claimants  for  unjust  damages,  as,  for  instance,  in 
the  case  of  punch  and  shear  castings,  which  are  often 
broken  by  reason  of  carelessness  on  the  part  of  work- 
men or  attempts  being  made  by  the  proprietors  to 
utilize  a  machine  above  the  strains  guaranteed.  For 
if  the  builder  can  prove  that  previous  castings,  which 
had  tests  recorded  from  test  bars,  had  stood  the  guar- 
anteed strains  to  compare  closely  with  the  casting  that 
broke,  he  cannot  be  far  out  of  the  way  in  maintaining 
the  position  that  the  close  comparison  of  all  his  test 
bar  records  justified  him  in  assuming  that  all  castings 
made  from  that  one  pattern  should  be  closely  alike, 
for  the  reason  that  they  can  be  classed  under  the  head  of 


530  METALLURGY    OF    CAST    IRON.    - 

duplicates  similarly  as  cited  above  for  car  wheels,  etc. , 
the  only  difference  being  that  these  single  castings  are 
not  cast  in  large  numbers  and  may  have  months  inter- 
vening between  their  production,  so  that  in  a  practical 
sense  castings  can,  when  they  are  occasionally  dupli- 
cated, have  the  test  bar  records  accepted  to  denote 
their  physical  qualities  in  a  comparative  manner,  as 
where  any  number  of  castings  are  steadily  or  daily 
made  from  the  same  pattern. 

The  utility  of  the  test  bar  is  being  more  and  more 
recognized  and  made  use  of.  The  author  believes 
that  within  ten  years  almost  all  founders  and  engi- 
neers will  recognize  standards  for  physical  tests.* 
How  are  we  going  to  be  able  to  make  intelligent 
comparisons  with  our  own  records  or  those  of  others, 
where  we  find  bars  as  small  as  one-half  inch  square 
to  two  inches  square  being  used,  and  some  of  rectan- 
gular form  and  again,  it  can  be  said,  in  all  kinds  of 
lengths,  from  a  foot  up  to  four  feet  long,  so  that  we 
practically  find  hardly  two  founders  using  the  same 
form  or  length  of  a  bar,  or  builders  and  engineers 
exacting  the  same  character  of  tests?  Some  will  say 
that  the  difference  in  both  the  length  and  area  of  such  a 
variety  of  bars  could  be  computed  to  strength  per 
square  inch,  in  making  comparisons.  It  can  be  shown 
(see  Chapter  LXL,  page  476)  that  there  is  about  as  much 
difference  to  be  found  in  formulas  for  computing  stich 
variations  as  is  found  above  in  test  bars,  and  also  that 
so  eminent  and  able  an  authority  as  Prof.  C.  H. 

*  Many  consider  that  the  distribution  of  the  first  two  editions  of 
this  work,  in  connection  with  the  author's  advocacy  of  round 
bars  cast  on  end  in  trade  papers,  is  largely  responsible  for  the 
conditions  leading  up  to  the  recommendation  by  the  American 
Foundrymen's  Association  of  the  proposed  standards  seen  in  the 
next  chapter. 


UTILItY    OF    THE    TEST    BAR,     ETC.  531 

Benjamin,  of  the  Case  School  of  Applied  Science,  has 
shown  that  formulas  used  prior  to  1901  are  unsuited 
and  incorrect  for  figuring  the  strength  of  cast  beams,  etc. 

The  prevailing  practice  of  recording  tests  to-day  may, 
in  some  cases,  where  test  bars  not  less  than  of  one  inch 
area  are  used,  be  accepted  as  an  approximation  in  so  far 
as  relates  to  a  firm's  own  practice  in  making  com- 
parisons for  mixture,  with  permanent  hands,  but 
should  a  firm  desire  to  bring  in  a  new  manager  or 
tester,  who  has  been  guided  in  rulings  or  records  ob- 
tained from  other  shop  practice  or  systems,  his  past 
experience  will  prove  of  very  little  value  to  him; 
hence  the  firm  must  lose  in  many  ways  before  the  new 
man  is  enabled  to  be  rightly  guided  by  information 
which  he  can  deduce  from  his.  new  system.  Then, 
again,  a  manager  or  tester  in  making  any  changes 
from  one  work  to  another  is  also  a  loser  and  is  sub- 
jected to  the  same  inconveniences,  etc. ,  just  mentioned. 
This  shows  us  that  both  sides  can  lose  some,  say- 
ing nothing  as  to  what  is  lost  by  their  not  being  able 
to  make  intelligent  comparisons  with  the  outside 
foundry  and  engineering  world,  or  with  blast  furnaces 
from  which  large  quantities  of  pig  metal  must  and 
should  be  intelligently  purchased.  Present  practice 
shuts  us  up  like  a  clam,  and  makes  us  dead  to  all  the 
benefits  which  a  standard  of  physical  tests  could  in- 
sure. Progression  demands  something  broader  and  of 
more  correct  utility  than  the  practice  of  1901  insures. 

In  reviewing  tests  recorded  of  test  bars  or  castings 
in  our  engineering  text-books  of  the  past,  we  find  the 
practical  utility  of  the  same  to  be  largely  lost,  for  the 
reason  that  there  is  no  base  presented  upon  which  to 
formulate  mixtures,  to  duplicate  fairly  the  "  grade  "  of 


532  METALLURGY    OF    CAST    IRON. 

the  iron  comprising  the  casting  or  test  bar  whose 
strength,  etc. ,  has  been  recorded.  If  for  each  test  of 
all  such  castings  or  test  bars  we  had  a  standard  sys- 
tem, we  could  then  by  referring  to  the  tests  of  any 
mixtures  in  our  own  practice  which  had  recorded  simi- 
lar physical  qualities  in  a  test  bar,  be  at  once  in  a 
very  favorable  position  to  obtain  or  produce  a  similar 
casting,  having  like  physical  qualities.  Some  might 
suggest  chemical  analyses  of  the  castings  being  re- 
corded in  order  to  give  a  base  for  making  comparisons 
and  duplication  of  like  castings.  This  would  work 
admirably  in  all  cases,  but  of  the  two  methods  the 
physical  test  is  often  more  economical  and  practical 
for  adoption  by  some  founders,  for  the  reason,  that 
there  are  some  who  can  generally  conduct  physical 
tests,  but  who  cannot  maintain  a  laboratory  with  its 
chemist,  or  engage  outsiders.  Even  where  founders 
are  equipped  with  laboratories,  the  physical  tests  are 
necessary  as  a  ''hand-maid,"  to  tell  what  is  being 
achieved,  and  still  further  argue  for  the  advisability 
of  a  standard  system  of  physical  tests. 

II  there  were  no  difference  in  the  •« grade"  of  an 
iron  to  make  a  difference  in  the  hardness,  strength, 
contraction,  etc.,  of  mixtures  or  castings,  then  we 
would  not  require  any  physical  tests,  but  when  we 
consider  mixtures  of  iron  can  be  made  ranging  all 
the  way  from  600  to  4,000  pounds,  with  one  square 
inch  area  bars  twelve  inches  between  supports,  it 
plainly  illustrates  the  benefits  to  be  derived  by  accom- 
panying a  casting  with  tests  obtained  from  the  same 
ladle  or  iron  by  means  of  suitable  test  bars,  whether 
the  strength  is  obtained  by  means  of  transverse  or 
tensile  tests  to  make  comparisons. 


UTILITY    OF    THE    TEST    BAR,    ETC.  533 

Because  the  1^3 -inch  round  bar  is  large  enough  not 
to  have  its  carbon  severely  distorted  to  make  tests 
erratic  or  belie  the  ruling  power  of  the  percentage  of 
iron,  etc.,  in  the  metal,  by  the  chilling  influence  of  a 
green  sand  mould,  and  also  because  it  is  not  so  small 
but  that  strong  grades  can  often,  for  rough  estimates, 
be  used  for  comparison  with  weak  grades  on  low-priced 
testing  machines,  are  reasons  why  the  author  used  a 
bar  as  small  as  i^-inch  diameter  as  one  standard  for 
making  comparative  tests.  Having  shown  in  many 
tests,  (page  468)  that  the  i  ^6 -inch  round  bar  will  fairly 
record  degrees  in  the  strength  of  cast  iron  to  fairly 
agree  in  a  comparative  way  with  the  commercial  value 
attached  to  the  strengths  of  the  various  mixtures  rang- 
ing from  stove  plate  up  through  light  machinery,  heavy 
machinery,  car  wheel,  chill  roll  and  gun  metal,  the 
author  would  now  refer  to  two  other  sizes,  i^-inch 
and  irl-inches  diameter  as  being  also  well  fitted  for 
recognition  as  standard  bars."  The  two  latter  sizes  of 
bars  are  best  utilized  by  founders  who  may  make  mix- 
tures containing  less  than  1.50  in  silicon  and  above  .04 
in  sulphur.  For  those  above  1.75  in  silicon  and  below 
.07  in  sulphur  in  the  test  bar  or  casting,  the  i ^6 -inch 
diameter  bar  will  be  found  to  generally  record  fair 
comparisons  in  degrees  of  strength.* 

It  is  to  be  understood  that  while  either  size  of 
the  above  three  proposed  standard  bars  would 
not  err  much  in  recording  true  degrees  in  the 
strength,  deflection,  and  contraction  where  com- 
parisons are  to  be  made  in  any  one  "grade"  or  in 

*  While  the  i^-inch  round  bar  will  answer  fairly  well  for  mak- 
ing general  comparisons  in  all  irons  having  over  1.75  silicon 
and  under  .07  sulphur,  still  the  author  approves  the  recommenda- 
tions found  on  page  573,  which  show  that  test  bars  should  not  be 
smaller  than  i^  inches  in  diameter,  and  cast  on  end,  as  such  will 
give  truer  results  than  the  i^-inch  round  bar  in  general  practice, 
especially  in  making  comparison  of  the  widest  ranges  in  grades. 


534  METALLURGY    OF    CAST    IRON. 

all  of  them,  the  same  size  bar  must  be  used.  One  size 
bar  cannot  be  used  for  one  per  cent,  silicon  iron  and 
then  dropped  and  another  taken  up  to  test  percentages 
above  or  below  this.  (See  Chapter  LXVII.,  page  520.) 
Whatever  size  of  a  common  sense  bar  the  testers  use, 
in  making  comparison  through  any  range  of  work, 
they  must  stick  to  that  one,  and  then,  if  they  desire  to 
make  comparison  with  outside  records  that  have  been 
obtained  with  standard  bars  other  than  the  one  size 
they  use,  they  would  then  be  compelled  to  make  tests 
with  the  same  size  of  bars  which  was  used  to  ob- 
tain the  outside  test.  Of  course,  if  a  firm  desired,  they 
could  cast  the  three  sizes  of  bars  together,  mentioned 
on  page  533,  with  the  same  ladle  of  iron,  and  thus  al- 
ways have  at  hand  records  by  which  they  could  make 
comparisons  on  a  moment's  notice,  with  any  outside 
tests  that  had  been  obtained  with  either  of  the  three 
standard  sizes  of  bars  mentioned  herein.* 

The  following  Tables,  108  to  113,  pages  536  and  537, 
display  tests  of  the  author's  proposed  three  sizes  of 
standard  bars,  accompanied  with  a  chemical  analysis 
of  the  various  mixtures  shown  to  still  increase  their 
value.  A  study  of  these  Tables  (combined  with  those 
of  Chapter  LX.,  page  460),  the  author  believes,  will 
sustain  him  in  his  advocacy  of  the  i^-inch,  1^5 -inch 
and  i |f -inch  round  test  bars  as  well  fitted  for  and  to 
maintain  a  standard  of  comparative  physical  tests. 

The  tests  presented  are  obtained  from  the  actual 
mixtures  used  for  pouring  castings  in  the  various 
specialties  mentioned,  and,  as  seen,  are  arranged  in  the 
order  of  their  strength.  Double  the  amount  of  tests 
were  made,  but  those  shown  illustrate  the  relation  of 
the  different  areas  in  strength  per  square  inch  as 

*  For  three  other  standards,  see  pages  573,  577  and  579. 


UTILITY    OF    THE    TEST    BAR,     ETC.  535 

well  as  large  numbers  could,  and  make  study  an  easy 
task  to  readily  demonstrate  their  utility  as  being  suit- 
able for  standard  comparative  tests. 

The  tests  shown  are  all  of  solid  bars  cast  on  end, 
and  they  illustrate  among  other  valuable  features  the 
fact  that  the  two  and  three  square  inch  area  round  bars 
record  a  greater  strength  per  square  inch  than  the  one 
square  inch  area  round  bars.  This  series  of  tests  also 
shows  conclusively  that  no  one  should  use  a  test 
bar  smaller  than  of  one  square  inch  area  with  the 
expectation  of  making  any  fair  comparisons  of 
degrees  in  the  strength,  etc.,  of  his  irons.*  While 
the  one  square  inch  area  round  bar  shown  does  not 
record  the  high  strength  for  strong  metals  that  the 
larger  bars  do,  it  is  made  very  evident  that  they  do 
record  degrees  of  strength  fairly  accurate  for  use 
in  a  comparative  test  for  soft  irons  or  those  above  1.50 
in  silicon  for  ordinary  testing,  a  fact  also  demonstrated 
by  the  specialty  tests  as  seen  in  Table  96,  page  466, 
showing  a  gradual  rise,  in  denoting  degrees  of  .strength 
in  different  grades  of  iron  ranging  from  1,480  to  3,686 
pounds  per  square  inch. 

The  test  bars  shown  in  this  chapter  were  cast  during 
the  month  of  May,  1896,  and  were  kindly  supplied  by 
the  foundries  of  the  Lloyd-Booth  Co. ,  Youngstown,  O. , 
Philadelphia  Roll  &  Machine  Co.,  A.  Whitney  &  Sons, 
both  of  Philadelphia,  Pa.,  the  Shenango  Machine  Co., 
and  Graff  Stove  Foundry  Co. ,  both  of  Sharon,  Pa.  The 

test  of  "  Bessemer,"  Table  113,  was  cast  by  the  author. 
Tables  1 08,  no,  in,  112,  and  113  were  tested  by  Prof. 

C.  H.  Benjamin  at  the  Case  School  of  Applied  Science, 
*This  is  in  keeping  with  the  recommendations  of  the  A.  F.  A., 

not  to  use  bars  smaller  than  i  yt  inches  in  diameter.     (See  next 

chapter.) 


S3* 


METALLURGY    OF    CAST    IRON. 


and  those  of  Table  109  by  the  Riehle  Bros.,  of  Philadel- 
phia, Pa.  The  relative  strength  per  square  inch  is 
obtained  by  dividing  the  actual  breaking  load  by  the 
area  of  the  bar,  at  its  point  of  fracture.  (For  rule,  see 
page  476.) 

TRANSVERSE  TESTS    OF    SPECIALTY    IRONS    WITH     ONE,    TWO    AND     THREB 
SQUARE  INCH  AREA  TEST  BARS. 

TABLE  IO8.— CHILL    ROLL    IRON. 


No  of 
test. 

Diam.  of  bar. 
Common  rule. 

Microm- 
eter. 

Breaking 
load. 

Area 
of  bar. 

Stre'gth  per 
sq.  in.  in  Ibs. 

De- 
flection. 

i 

\yr 

1.140" 

3,250 

1.021 

3,i83 

0.105 

2 

*w 

1-655" 

9,5oo 

2.151 

4,4i7 

0.090 

-    3 

1  15-16" 

1.968" 

15,250 

3.042 

5,oi3 

0.085 

TABLE  lOQ.— GUN    CARRIAGE   METAL. 


No.  of 
test. 

Diam.  of  bar. 
Common  rule. 

Microm- 
t      eter. 

Breaking 
load. 

Area 
of  bar. 

Stre'gth  per 
sq.  in.  in  Ibs. 

De- 
flection. 

4 

i-yf 

1.  122" 

2,780 

.988 

2,812 

O.IOO 

5 

i%" 

1.664' 

9,250 

2.174 

4,254 

O.IIO 

6 

i  15-16" 

1.859" 

11,820 

2.714 

4,355 

O.IOO 

TABLE  1 10 CAR    WHEEL    IRON. 


No.  of 
test. 

Diam.  of  bar. 
Common  rule. 

Microm- 
eter. 

Breaking 
load. 

Area 
of  bar. 

Stre'gth  per 
sq.  in.  in  Ibs. 

De- 
flection. 

7 

i1/*" 

1.174" 

2,200 

1.082 

2,033 

°°53 

8 

itt" 

1.691" 

8,100 

2.244 

3,610 

0.070 

9 

i  15  16" 

2.008" 

13,500 

3-167 

4,263 

o  072 

TABLE  1 1 1. —HEAVY    MACHINERY    IRON. 


No.  of 
test. 

Diam.  of  bar. 
Common  rule. 

Microm- 
eter. 

Breaking 
load. 

Area 
of  bar. 

Stre'gth  per 
sq.  in.  in  Ibs. 

De- 
flection. 

10 

i  %" 

1.187" 

2,800 

1.1066 

2,530 

0.092 

ii 

iH" 

1.705" 

7,100 

2  282 

3"i 

0,072 

12 

i  15-16" 

2  OOl" 

11,900 

3-M3 

3786 

0.079 

UTILITY    OF    THE    TEST    BAR,    ETC. 


537 


The  chemical  analyses  seen  in  Table  114  were  kindly 
furnished  by  Dickman  &  Mackenzie,  of  Chicago,  and 
Dickman  &  Crowell,  of  Cleveland. 

Aside  from  the  attention  which  has  been  called  by 
this  paper  to  various  points  in  the  following  tests, 
there  are  two  factors  which  some  may  be  at  a  loss  to 
understand.  The  first  is  the  break  in  the  gradual  in- 

TABLE  112.— STOVE   PLATE    IRON. 


No.  of 
test. 

Diam.  of  bar. 
Common  rule. 

Microm- 
eter. 

Breaking 
load. 

Area 
of  bar. 

Stre'gth  per 
sq.  in.  in  Ibs. 

De- 
flection. 

13 

i%" 

1.182" 

2,5-0 

1.097 

2,288 

0.117 

14 

i%" 

1-745" 

6,050 

2391 

2,530 

0.078 

15 

i  15-16" 

2.047" 

9,900 

3.288 

S.oii 

0081 

TABLE  113.— BESSEMER    IRON. 


No.  of 
test. 

16 

Diam.  of  bar. 
Common  rule. 

Microm- 
eter. 

Breaking 
load. 

Area 
of  bar. 

Stre'gth  per 
sq.  in.  in  Ibs 

De- 
flection. 

iW 

1.175" 

2,150 

1.084 

i,983 

O.IOO 

17 

iW 

1.698" 

5,5oo 

2.263 

2,43s 

O.IOO 

18 

1  15-16" 

1.991" 

8,900 

3-"2 

2,860 

0.085 

TABLE  114.— CHEMICAL   ANALYSIS. 


Specialty. 

Silicon 

Sulphur. 

Mang. 

Phos. 

Comb. 
Carbon. 

Graph. 
Carbon. 

Total. 

Chill  Roll  

.84 

.071 

.285 

•547 

.61 

245 

3-06 

Gun  Metal 

77 

OSQ 

408 

76 

Car  Wheel  

.78 

.132 

.306 

•364 

1.07 

2.36 

343 

General 
Machinery  

1.30 

•053 

.224 

•433 

•58 

33i 

3.89 

Stove  Plate  

2-47 

.094 

.265 

.508 

•19 

4.00 

4.19 

Bessemer 

I  S2 

O5Q 

•126 

081 

49, 

•i  7* 

A  22 

538  METALLURGY    OF    CAST    IRON. 

crease  of  strength  of  the  i}^  bars,  which  is  displayed 
by  test  No.  7  being  weaker  than  tests  Nos.  4  and  10. 
This  is  due  to  the  high  sulplmr  in  the  iron  when  in 
a  small  body  as  of  i^4  inches  diameter,  causing  the 
combined  carbon  to  overreach  its  limit  for  gradually 
increasing  the  strength  of  the  i  ^6 -inch  bars,  as  shown 
by  the  break  in  tests  Nos.  i,  4,  10,  13,  and  16.  Test 
No.  7  is  one  which  strongly  emphasizes  the  wisdom 
of  not  using  bars  smaller  than  i^  inches  in  diameter 
where  the  best  comparative  records  are  desired,  and 
strongly  endorses  the  A.  F.  A.  recommendations, 
seen  on  page  577.  The  second  factor  is  that  shown  by 
the  low  strength  displayed  by  the  ' '  Bessemer  ' '  iron 
shown  in  Table  113.  Had  the  "  iron  "  in  the  Bessemer 
Table  113  been  near  the  percentage  seen  in  Table  in, 
for  heavy  machinery,  the  strength  of  the  test  bars  in 
Table  113  should  have  nearly  equalled  that  of  Table 
iit.  To  note  the  influence  of  "  iron  "  on  the  strength 
of  grades,  see  Table  37,  page  250. 


CHAPTER  LXX. 

METHODS   OF   CASTING  TEST  BARS  FOR 

THE  A.  F.  A.  TESTS,  COMPILATION 

AND  SUMMARY  OF  RESULTS. 

Prior  to  about  1890,  there  had  been  felt  for  many 
years  the  need  of  tests  on  cast  iron,  to  give  those  inter- 
ested in  its  use  reliable  data  of  its  physical  qualities. 
Some  work  had  been  done  in  an  effort  to  obtain  records 
that  could  be  used,  but  before  the  appointment  of  the 
American  Foundrymen  Association's  committee,  in  the 
spring  of  1898,  little  of  practical  value  had  been 
obtained  aside  from  that  presented  in  the  first  two 
editions  of  this  work.  This  was  due  in  part  to  the 
want  of  a  broad  experience  in  founding  by  experi- 
mentors,  and  their  inability  to  originate  practical 
methods  for  moulding  and  casting  test  specimens  in 
the  right  manner.  Some,  for  one  example,  started  off 
with  an  elaborate  series  of  tests  on  one  grade  of  iron 
only,  thinking  that  such  would  suffice,  when  in  reality 
there  are  about  a  dozen  grades  that  should  be  con- 
sidered. Aside  from  this  error  the  bars  were  all  cast 
flat,  and  at  different  pouring  temperatures. 

The  unreliability  of  records  and  systems  for  testing 
that  were  pressed  on  the  trade  from  1890  to  1899  caused 
the  author  to  labor  in  every  way  he  could  to  show 
wherein  they  erred,  and  to  get  others  interested  suffi- 


540  METALLURGY    OF    CAST    IRON. 

ciently  to  help  bring  about  a  series  of  tests  that  would 
result  in  giving  the  engineering  and  foundry  world 
elaborate  records  of  tests,  secured  through  means  that 
recognized  the  different  grades,  and  the  importance  of 
having  all  tests  in  any  one  grade  poured  at  the  same 
temperature.  The  many  tests  and  papers  which  the 
author  presented  demonstrating  the  errors  of  past 
methods  of  testing  cast  iron,  finally  resulted  in  awak- 
ening foundrymen  and  others  to  the  necessity  of  taking 
some  action  in  the  matter;  and  by  the  valuable  assist- 
ance and  efforts  of  Dr.  Richard  Moldenke,  the  author 
had  the  pleasure  of  seeing  the  A.  F.  A.  appoint  a  com- 
mittee, at  its  annual  convention  in  1898,  to  obtain  such 
tests  as  were  thought  necessary.  This  committee 
consisted  of  Dr.  Richard  Moldenke,  Messrs.  James 
S.  Sterling,  Joseph  S.  Seamen,  Joseph  S.  McDonald, 
and  the  author.  The  first  work  of  the  committee 
was  to  outline  the  kind,  sizes,  and  number  of  test 
bars,  and  the  method  of  moulding  and  casting.  The 
latter  was  left  wholly  to  the  author,  as  he  had 
stated  that  he  could  devise  a  method  whereby  a  large 
number  of  different  sized  test  bars,  comprising  green 
sand  and  dry  sand  moulds  as  desired,  could  all  be  cast 
on  end,  from  one  ladle  of  iron  inside  of  thirty  seconds, 
thus  insuring  all  bars  of  any  one  set  being  poured  with 
metal  of  practically  the  same  temperature.  Some 
doubted  the  practicability  of  such  an  achievement,  and 
not  until  after  the  first  set  of  192  bars  were  cast  on 
end  from  one  ladle,  within  twenty  seconds  and  no  bars 
lost,  was  such  recognized  as  being  feasible.  This  was 
an  achievement  that  should  place  all  the  tests  of  the 
A.  F.  A.  on  a  plane  far  above  all  others  ever  made ;  at 
least,  all  who  have  noted  to  any  degree  the  variations 


METHODS  OF  CASTING  TEST  BARS  FOR  THEIA.  M  AN- V  B5PW5  f TV 


OF 


542  METALLURGY    OF    CAST    IRON. 

that  can  exist  in  the  physical  qualities  of  cast  iron  due 
to  variations  in  the  pouring  temperatures,  must  per- 
ceive its  importance. 

The  first  cast  of  the  test  bars,  also  the  chill  and 
fluidity  test  pieces,  are  seen  at  Fig.  131,  page  541. 
The  patterns  and  core  boxes  used  are  shown  in  Figs. 
132  to  136.  At  Fig.  137  is  seen  one  of  the  malleable 
iron  flasks  used  for  making  the  green  sand  bars  from 
the  mould  boards  seen  in  Figs.  133  and  134,  pages 
544  and  546.  The  flask,  as  shown,  is  -clamped  and  up- 
ended ready  for  lowering  into  the  casting  pit,  to  be 
placed  as  seen  at  K,  Fig.  138,  page  550.  The  making 
of  all  these  patterns,  core  boxes,  and  flasks  was 
under  the  supervision  of  Dr.  R.  Moldenke  while 
engaged  as  metallurgist  with  McConway  &  Torley 
of  Pittsburg,  and  who  donated  them  to  the  com- 
mittee in  the  interest  of  the  trade.  Doctor  Moldenke 
is  to  be  credited  with  having  done  most  of  the  work  in 
making  the  patterns  and  fitting  up  the  flasks. 

The  floor  space  required  for  casting  a  full  set  of 
these  bars  was  eight  feet  wide  by  eighteen  feet  long, 
dug  out  to  make  a  pit  about  three  feet  deep.  The 
time  required  to  mould  and  cast  a  full  set  as  shown  in 
Fig.  131  involved  about  thirty  days'  labor.  The  first 
set  was  made  under  the  author's  close  supervision;  in 
fact,  he  did  considerable  of  the  work.  After  the  pit 
was  dug  out  a  level  floor  was  made  in  the  bottom  and 
all  the  green  sand  moulds  and  cores  were  set  in  place  after 
the  manner  shown  in  Fig.  138.  These  set,  sand  was 
rammed  around  all  the  flasks  and  cores  up  to  the 
level  of  K  and  W,  Fig.  140,  page  552,  after  which  a 
double  row  of  vents  was  made  down  each  side  of 
the  cores  and  flasks.  A  bed  of  fine  cinders  was  next 


METHODS  OF  CASTING  TEST  BARS  FOR  THE  A.  F.  A.       543 


8 

£ 

ci    ^ 

:"1 


544 


METALLURGY    OF    CAST    IRON. 


rt  jo 
ifl    . 


METHODS  OF  CASTING  TEST  BARS  FOR  THE  A.  F.  A.       545 

laid  at  the  level  of  K  and  W,  as  shown  by  the  black 
dots  in  Fig.  140.  The  cinders  were  also  brought  out 
to  come  under  the  pouring  basin  A,  Figs.  139  and  142, 
pages  552  and  554,  after  which  cores  to  form  the  gate 
connection  G  and  risers  E,  seen  in  Figs.  138  and  139, 
were  placed  in  position  as  shown,  and  sand  was  then 
rammed  up  to  a  level  of  the  top  of  the  cores  and 
moulds.  To  keep  the  dirt  from  dropping  into  the 
mould  through  the  gate  holes  seen  at  W,  Fig.  138 ;  while 
ramming  up  the  pit,  boards,  to  cover  the  gate  holes 
(not  shown),  were  used.  After  the  pit  was  rammed  up 
to  a  level  of  the  top  of  the  cores  and  flasks,  these  boards 
were  removed  and  runner  patterns  of  the  form  seen 
at  Fig.  136,  page  548,  were  then  placed  over  the  cores 
to  form  runners  in  connection  with  the  main  basin  A, 
as  seen  at  Fig.  140.  This  done,  plates  were  set  on  edge 
as  at  M,  S,  and  X,  after  which  the  inlet  plate  H  was  set 
up  against  the  plates  S,  and  plates  as  at  B  set  against 
its  ends  after  the  manner  shown.  This  completed,  a 
board  12  inches  deep  by  15  feet  long  was  braced  n 
inches  away  from  the  face  of  H  and  the  whole  bed  was 
then  rammed  up  and  finished  to  appear  as  seen  at  Fig. 
142.  This  cut  also  shows  men  in  position  to  test  lifting 
the  inlet  plate  H  by  means  of  levers  Y,  resting  on  the 
plate  M,  to  come  under  lugs  N.  Stops,  as  at  P,  pre- 
vented the  inlet  plate  being  lifted  to  any  greater  height 
than  2^/2  inches,  which  insured  clean  metal  only  passing 
to  the  moulds,  as  when  the  basin  A  was  filled  by  the 
ladle  U,  as  seen  on  page  556,  all  dirt  was  confined  and 
remained  upon  the  surface  of  the  metal  in  the  basin 
A.  Two  risers  were  carried  from  the  two  outside 
flasks,  as  at  E,  and  left  uncovered  when  casting,  so 
that  when  the  moulds  were  filled  all  surplus  metal 


546 


METALLURGY    OF    CAST    IRON. 


CO 

M       O 


METHODS  OF  CASTING  TEST  BARS  FOR  THE  A.  F.  A.       547 

remaining  in  the  basin  and  runners  flowed  out  readily 
to  pig  beds  having  a  lower  level  than  the  pouring  basin 
and  runners  as  seen  at  C,  Figs.  142  and  143,  thus  leav- 
ing the  moulds  disconnected  to  be  removed  singly  from 
their  casting  pits  after  the  gate  connections  between 
the  flasks  at  G  were  broken.  The  basin  A  being,  as 
shown,  one  foot  wide  and  deep,  gives  a  body  of  fluid 
iron  weighing  about  three  tons,  uniform  in  tempera- 
ture. And  when  it  is  said  that  from  the  moment  the 
inlet  plate  H  was  lifted  to  the  time  the  192  test  bars 
and  two  chill  blocks,  all  weighing  when  cleaned  3,780 
pounds,  were  all  poured  scarcely  twenty  seconds 
passed  and  no  bars  were  lost,  all  will  realize  the  suc- 
cess achieved. 

Casting:  half  the  bars  in  dry  sand  cores  was  done  for 
the  purpose  of  making  a  comparison  between  the 
effects  of  a  green  and  dry  sand  mould  and  to  give 
greater  completeness  to  the  results.  The  dry  sand 
bars  were  made  in  cores  instead  of  iron  flasks,  for  the 
reason  that  it  was  thought  that  some  of  the  shops  the 
work  was  assigned  to  might  not  be  in  a  position  to  dry 
the  dry  sand  moulds,  but  could  handle  the  cores. 

In  making  the  cores  it  was  very  desirable  to  have 
them  of  a  character  that  would  crush  easily  when  the 
bars  commenced  to  contract,  as  anything  preventing 
this  might  strain  the  bars  internally  so  as  not  to  give 
a  true  test.  The  author  adopted  the  following  mixture 
for  making  the  cores: 

i  part  lake,  river,  or  bank  sand, 

3  parts  fine  silica  or  crushed  sand, 

i  part  rosin  to  25  parts  of  sand, 

i  part  of  flour  to  25  parts  of  sand 

i  part  glutrose  to  30  parts  sand. 
Wet  balance  with  water. 


METALLURGY    OF    CAST    IRON. 


FIG.    135. 


The  core  mixture  mentioned 
possesses  very  little  body  to 
stand  up  in  a  green  state ;  so 
little  that,  in  making  the 
larger  cores,  rodding  was  very 
necessary,  in  order  to  hold 
the  cores  together.  When 
this  mixture  is  dry  the  cores 
are  exceptionally  strong  to 
handle,  but  crush  very  easily 
when  the  castings  commence 
to  contract.  To  form  the 
small  neck  in  the  green  sand 
tensile  test  bars  as  at  D, 
Fig-  133,  cores  made  of  the 
above  mixture  were  used  as 
at  F  above,  Fig.  136.  This 
division  in  the  tensile  test  bars  was  made  for  the  pur- 
pose of  giving  a  long  and  very  short  test  specimen. 

To  obtain  the  contraction,  a  device,  Fig.  144,  page 
557>  was  arranged  so  as  to  punch  ^-inch  holes  in  the 
cores  and  green 
sand  molds. 
These  formed 
pins  in  the 
mould  that  were 
exactly  12 
inches  apart, 
so  that  when  the 
castings  were 
cold  the  con- 
traction could 
be  accurately  r  »  '»  FIG.  I36. 


METHODS  OF  CASTING  TEST  BARS  FOR  THE  A.  F.  A.       549 


55° 


METALLURGY    OF    CAST    IRON. 


METHODS  OF  CASTING  TEST  BARS  FOR  THE  A.  F.  A.          551 

measured.  The  few  records  shown  will  give  a  fair 
idea  of  the  ratio  of  contraction  in  the  large  and  small 
bars. 

To  obtain  the  chill,  the  author  devised  the  form  of 
test  block  seen  in  Figs.  135  and  145,  pages  548  and 
559.  It  was  made  of  the  wedge  form  seen,  so  that 
the  block  could  be  used  throughout  all  the  different 
grades.  These  chilled  tests  were  cast  in  a  core  having 
one  face  part  chill  and  part  core,  as  seen  at  E'  and  Hx, 
Fig.  135.  The  chill  E'  was  i%  inches  thick!  The 
chill  tests,  Figs.  145  to  147,  pages  559  and  563,  chilled 
but  slightly  at  the  top  points  and  face,  while  the  chill 
for  chilled  rolls  (not  shown)  are  all  chilled,  showing 
the  hard  nature  of  iron  used  for  chilled  rolls,  etc. 

The  fluidity  of  the  metal  was  tested  by  means  of 
two  fluidity  strips  jMi  inch  thick  at  their  base,  running 
up  to  a  knife-edge  14  inches  long,  as  seen  at  X,  Figs. 
131  and  135,  pages  541  and  548.  The  principle  in- 
volved in  these  fluidity  strip  tests  is  the  same  as  de- 
scribed for  those  .shown  on  pages  515  to  517,  and  they 
serve  to  show  the  difference  that  might  exist  between 
the  fluidity  of  the  various  sets  of  test  bars  that  were 
made  and  noticed  in  connection  with  the  tests  recorded 
from  pages  558  to  570. 

The  different  kinds  of  physical  tests  consisted  of 
transverse,  deflection,  tensile,  compression,  contrac- 
tion, and  chill  tests.  The  bars  varied  in  size  from  y% 
inch,  square  and  round,  increasing  ^  inch  in  size  in 
each  class  up  to  4  inches  square  and  4^  inches  round 
for  transverse  tests,  and  from  %  inch  square  and 
round  to  about  2  inches  square  and  2^  inches  round 
for  tensile  tests.  There  were  four  bars  of  each  kind 
and  size  made  in  green  sand  and  four  bars  of  each 


55* 


METALLURGY    OF    CAST    IRON. 


— SI— 


o 


o 


METHODS  OF  CASTING  TEST  BARS  FOR  THE  A.  F.  A.       553 

maae  in  dry  sand,  making1  a  total  of  eight  bars  of  each 
kind.  Nearly  one-half  of  the  total  number  was 
finished  by  being-  planed  if  square,  and  turned  if  round 
bars,  so  as  to  make  a  comparison  between  the  rough 
cast  bars  and  those  which  had  a  trifle  more  than  % 
inch  of  stock  removed  from  their  surface.  This  was 
done  by  finishing  down  the  rough  bars  to  correspond 
in  size  to  those  of  next  smaller  dimensions  as,  for 
example,  a  4^ -inch  rough  bar  was  turned  down  to  a 
4-inch  bar,  and  a  4-inch  bar  down  to  a  3% -inch  bar, 
and  so  on  until  a  i-inch  rough  bar  was  finished  to  a 
^-inch  bar.  This  finishing  work  was  chiefly  done  by 
Dr.  R.  Moldenke. 

There  were  1,601  tests  made  on  1,229  test  barsi  not 
counting  the  chilled  pieces  and  fluidity  strips,  making, 
roughly,  15  tons  of  test  specimens  that  were  handled. 
To  tabulate  all  the  tests  as  they  originally  appeared 
in  the  American  Foundrymen's  Association  Journals, 
and  which  were  originally  designated  from  A  to  L, 
making  a  total  of  1 2  different  grades  or  specialties  that 
were  tested,  would  require  more  space  than  could  be 
justly  given  here.  In  an  effort  to  condense  the  results 
of  the  A.  F.  A.  tests,  and  at  the  same  time  present  a 
fair  summary  of  the  whole,  the  author  has  omitted, 
excepting  in  one  or  two  instances,  all  tests  of  square 
bars  and  those  of  round  bars  cast  in  dry  sand,  which 
reduces  the  records  to  282  tests  as  shown  in  Tables 
115  to  126,  pages  558  to  570.  However,  a  study  of  what 
tests  are  presented  in.  connection  with  the  summary  at 
the  close  of  the  tables  will,  the  author  believes,  better 
serve  the  end  for  many  than  were  all  the  original  tables 
published,  without  reduction  or  comment  at  his  hands. 
The  work  involved  in  obtaining  these  tests  can  only  be 
known  by  those  who  have  followed  up  such  testing,  and 


554 


METALLURGY    OF    CAST    IRON. 


METHODS  OF  CASTING  TEST  BARS  FOR  THE  A.  F.  A.       555 

too  much  praise  cannot  be  accorded  Dr.  Richard  Mol- 
denke,  as  chairman,  for  the  great  zeal,  time,  and  much 
money  he  has  expended  in  supervising1  and  assisting  in 
the  accomplishment  of  this  work.  We  have  also  to  men- 
tion as  entitled  to  credit  Mr.  H.  E.  Diller  and  Mr.  A. 
Pechstein,  who  assisted  Dr.  Moldenke  in  making 
physical  tests  and  chemical  analyses.  Credit  is  also 
due  to  the  respective  persons  and  firms  mentioned  in 
connection  with  each  table  of  series  A  to  L,  for  their 
valuable  assistance  and  kindness  in  donating  the  cast- 
ings required  for  the  test  bars. 

The  transverse  bars  were  made  about  1 5  inches  long 
and  tested  1 2  inches  between  supports.  Any  depres- 
sions that  the  knives  might  make  in  the  surfaces  of  the 
round  or  square  bars  were  noted  in  recording  the 
deflection.  Two  tests  were  made,  on  an  average,  of 
each  kind  in  all  the  different  sizes  of  bars.  The  aver- 
ages of  the  two  tests  in  the  original  tables  of  the 
selected  bars  are  recorded  in  Tables  115  to  126,  so  as 
to  condense  the  results.  The  round  bars  are  selected 
in  preference  to  the  square  bars  in  compiling  Tables 
115  to  126,  for  the  reason  that  they  are  better  than 
square  bars,  as  is  explained  in  Chapter  LXIV. 

The  tensile  tests  in  original  tables,  all  of  which  were 
compiled  by  Dr.  R.  Moldenke,  were  reduced  to  strength 
per  square  inch  and  shown  in  connection  with  their 
actual  breaking  load,  but  the  author  has  separated  these 
so  as  to  give  the  strength  per  square  inch  of  the  tensile 
tests  in  the  independent  Table  126,  to  be  above  the 
chemical  analyses  of  the  different  specialties  shown  in 
Table  127,  both  seen  on  page  570.  The  actual  load  at 
which  tensile  bars  broke  is  shown  in  the  last  column  of 
casts  A,  B,  C  and  G  to  L.  The  form  of  bars  as  turned  - 
for  the  tensile  tests  is  seen  in  Fig.  148,  page  583. 

The  bars  cast  in  dry  sand  and  green  sand  showed 


556 


METALLURGY    OF    CAST    IRON. 


METHODS  OF  CASTING  TEST  BARS  FOR  THE  A.  F.  A.       557 

that,  as  a  rule,  those  cast  in  the  former  moulds  were 
weaker  than  in  the  latter.  One  hundred  tests  of  dif- 
ferent green  sand  bars,  averaging  closely  alike  in  size, 
gave  an  average  strength  of  33,700  pounds,  whereas 
ioo  tests  in  dry  sand  bars  gave  an  average  strength  of 
31,751  pounds,  showing  a  difference  of  1,949  pounds 
or  6  per  cent,  greater  strength  for  the  bars  in  green 
sand  than  those  in  dry  sand.  The  gray  iron  showed 
the  greatest  and  most  uniform  difference.  There 
were  a  few  casts,  in  both  the  chilled  and  gray  iron,  in 

which    the 
dry      sand 

.«— — «g  bars     aver- 

•  ^2f  XHBDi  ,  '  , 

aged      the 

gre  a  t  e  s  t 
strength. 
One  of  these 
varieties  is 
FIG-  J44-  shown  in  the 

unfinished  dry  sand  bars  of  Table  K  1 24,  page  568.  It  is 
natural  to  expect  the  green  sand  bars  to  show  the  great- 
est strength  on  account  of  the  chilling  influence  of  a 
damp  mould.  The  results  of  the  original  tables  shown 
in  the  A.  F.  A.  Journal  also  show  that  tests  of  green 
sand  bars  are  more  erratic  than  those  of  dry  sand, 
although,  as  a  rule,  the  difference  is  not  sufficient  to 
cause  the  dry  sand  bar  to  be  given  the  preference  in 
general  practice;  but  where  the  greatest  delicacy  in 
testing  is  desired,  by  the  use  of  unfinished  bars,  then 
the  dry  sand  bar  would  be  preferable.  The  author 
selected  the  bars  from  green  sand  for  the  Tables  115 
to  126  for  the  reason  that  such  are  almost  entirely  used 
in  general  practice,  and  hence  will  permit  of  a  better 


558 


METALLURGY    OF    CAST    IRON. 


comparison.  Further  summary  of  results,  especially 
those  illustrated  by  Tables  115  to  126,  are  given  by 
the  author  on  pages  571  and  574. 

TABLE   A-II5- — TESTS   OF    BESSEMER    IRON    CAST    AT  THE  THOS.   D.  WEST 
FOUNDRY    CO.,   SHARPSVILLE,   PA. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  finished 
green  sand  bars.* 

Tensile  tests  of  unfin- 
ished and  finished 
green  sand  bars. 

*i 
*J 

i 

is 

pC, 

bG 

11 

P31""1 

6   . 

H 

Il 

(j 

s* 

be 

ii 

«~ 

i* 

Us 
p*" 

*O  jj 

jtjj 

§s 

Sw 

Break'g 
load. 

•59 

445 

•  173 

9 

.56 

150 

•305 

16 

•57 

40,440 

2 

1.20 

2,440 

.130 

10 

1-13 

i,  sso 

•234 

i? 

i.i3 

13,630 

3 

1.78 

6,425 

.126 

ii 

1.69 

5.430 

.160 

18 

1.71 

28,860 

4_ 
5 

2-30 

13,965 

.110 

12 

2.15 

10,025 

.114 

19 

2.27 

44,830 

2.92 

24,320 

.101 

13 

2.82 

19,150 

.086 

*Fin 

ished 

}ars. 

6 
7 

3-44 
4.02 

36,875 

.100 

14 

3.38 

29.340 

.072 

20 

.56 

3,44° 

58,435 

.090 

15 

3-95 

51,985 

.079 

21 

1-13 

13,490 

8 

4-65 

77,335 

.082 

22 

1.69 

27,520 

*A11  the  finished  bars  shown  in  tests  Nos.  9  to  15,  as 
well  as  in  all  the  finished  bars  in  Tables  116  to  126, 
designated  by  stars,  were  made  of  rough  bars  cast  in 
green  sand  that  had  a  trifle  over  %  -inch  of  stock  turned 
off  their  surfaces.  As  an  illustration,  the  tensile  bars 
20,  21,  and  22  of  the  above  Table  115  were  of  the 
diameter  seen  in  transverse  tests  Nos.  10,  n,  and  12 
before  they  were  turned 

Compression  tests  from  bars  cast  in  dry  sand  of 
Table  115  showed  a  ^-inch  cube  cut  from  a  rough 
^-inch  bar  to  stand  29,570  pounds,  and  a  ^-inch  cube 
taken  from  the  center  of  a  i-inch  square  bar  20,010 
pounds;  from  the  center  of  a  2-inch  square  bar,  13,180 
pounds;  3-inch  square,  9,830;  and  4-inch  square,  9,100 
pounds. 

The  iron  used  for  Table  1 15  or  cast  A  was  an  all-coke 
pig  iron  mixture  having  about  5  per  cent,  scrap  melted 
in  a  cupola,  and  is  a  class  of  iron  used  for  castings  that 


FORM    OF    CHILL    TESTS    FOR    THE    A.  F.  A.  559 


FIG,      145. — FRACTURE  OF  CHILL  TEST  PIECE  IN  SERIES  A. 


560 


METALLURGY    OF    CAST    IRON. 


are  required  to  show  exceptional  service  under  high 
temperatures  or  severe  sudden  heating  and  cooling, 
causing  alternate  expansion  and  contraction  strains  in 
castings.  The  fluidity  strips  ran  up  full,  as  shown  in 
Fig.  131,  page  541.  The  contraction  ranged  from  .17 
for  the  ^-inch  bars  to  .03  in  the  4-inch  bars.  The 
chilling  qualities  of  the  iron  is  shown  in  the  test  piece, 
Fig.  145,  page  559.  The  chemical  analyses  of  Cast 
A,  and  all  others  to  Cast  L,  are  shown  in  Table  127, 
page  570.  This  first  cast  A  was  made  under  the  super- 
vision of  the  author 

TABLE   B-II6. — TESTS   OF   DYNAMO    IRON    CAST   AT    WESTINGHOUSE 
ELECTRIC   AND    MANUFACTURING    CO.,    PITTSBURG,  PA. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  finished 
green  sand  bars.* 

Tensile  tests  of  unfin- 
ished and  finished 
green  sand  bars. 

"Sii 

II 

il 

Pw 

be 

^-a 
£o 
M*"1 

6 

<U    r< 

<S.2 

»? 

ftj 

|s 

u 

5? 

bo 

!i 

li 

"0*: 

II 

^ 
a* 

be 
JN 

5| 

«*•* 

23 

.58 

2IO 

.106 

3i 

.56 

230 

.306 

38 

•58 

4,440 

24 

1.17 

2,300 

•125 

32 

1-13 

2,«5 

.160 

39 

1.  12 

15,540 

25 

1.74 

7,070 

.079 

33 

1.69 

6,120 

•"5 

40 

1.70 

29,140 

26 

2.26 

rsjSo 

.086 

34 

2-15 

11,065 

.080 

4i 

2.27 

46,580 

27 

2.86 

3i,47o 

.101 

35 

2.82 

24,  180 

•095 

*Fin 

ished 

bars. 

28 

3-47 

48,200 

•095 

36 

3.38 

4i,485 

•073 

42 

•56 

4,750 

29 

4.01 

73,550 

•093 

37 

3-95 

65,15° 

.065 

43 

1-13 

15,370 

30 

4.62 

100,  120 

.061 

44 

1.70 

27,200 

*For  references  to  meaning  of  the  star  in  Tables  116,  117,  120,  121,  122,  123  and 
125,  see  paragraph  following  Table  115,  page  558. 

Compression  tests  of  Table  1 16  from  bars  cast  in  dry 
sand  showed  a  ^-inch  cube  cut  from  a  rough  ^-inch 
square  bar  to  stand  38,360  pounds,  and  a  ^-inch  cube 
taken  from  the  center  of  a  i-inch  square  bar  23,000 
pounds;  from  the  center  of  a  2 -inch  square  bar,  18,130 
pounds;  3-inch  square,  13,790;  and  4-inch  square, 
12,430  pounds. 


FORM    OF    CHILL    TESTS    FOR    THE    A.  F.  A.  561 


FIG.   146. — FRACTURE  OF   CHILL   TEST   PIECES   IN   SERIES  B. 


56* 


METALLURGY    OF    CAST    IRON. 


The  iron  used  for  cast  B  was  soft  enough  to  machine 
readily  in  sections  little  more  than  ^  inch  thick.  A 
mixture  of  coke  and  charcoal  pig  iron,  with  about  40 
per  cent,  of  scrap,  was  used  and  melted  in  a  cupola. 
The  fluidity' strips  ran  up  nearly  full.  The  chilled  test 
pieces  gave  a  chill  of  about  1-16  inch  thick,  as  seen  in 
Fig.  146,  page  561.  This  cast  was  made  under  the 
supervision  of  Mr.  Jos.  McDonald. 

TABLE  C-II7- — TESTS    OF    LIGHT    MACHINERY    IRON    CAST    AT    WESTING- 
HOUSE  ELECTRIC  &  MFG.   CO.,  TITTSBURG,  PA. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  finished 
green  sand  bars.* 

Tensile  tests  of  unfin- 
ished and  finished 
green  sand  bars. 

*o 
d.1 

£~ 

iS 
Sw 

tt) 

ij 

«~ 

fed 

II 

0    . 

i! 

is' 

Qw 

Break'g 
load. 

fed 

& 

"o 
dl 

fc~ 

Diam- 
eter. 

Break'g 
load. 

45 

.56 

345 

•155 

53 

•56 

320 

•305 

60 

•57 

4,740 

46 

1.14 

2,320 

.119 

54 

1-13 

2,235 

.130 

61 

I-I3 

15,860 

47 

i-75 

6,940 

.085 

55 

1.69 

6,780 

.112 

62 

1.70 

32,020 
48,230 

48 

2.27 

16,330 

.079 

56 

2.15 

12,495 

.096 

63 

2.27 

49 

2.84 

31,030 

.088 

57 

2.82 

26,965 

-085 

*Fin 

ished 

bars. 

5° 

3-43 

50,200 

.074 

58 

3-38 

43,'iSO 

.086 

64 

•56 

4,340 

51 

3.98 

72,180 

.067 

59 

3-95 

72,695 

•075 

65 

1.  13 

14,990 

52 

4-63 

104,470 

.044 

66 

1.69 

26,030 

Compression  tests  from  bars  in  the  above  Table  117, 
cast  in  dry  sand,  showed  a  ^-inch  cube  cut  from  a 
rough  ^-inch  square  bar  to  crush  at  38,500  pounds, 
and  a  ^  -inch  cube  from  the  center  of  a  i  -inch  square 
bar  at  24,890  pounds;  from  the  center  of  a  2-inch 
square  bar,  18,010  pounds;  3-inch  square,  15,950,  and 
a  4-inch  square,  14,220  pounds. 

The  iron  used  for  cast  C  was  of  a  character  to  run 
into  very  thin  sections,  and  yet  be  soft  enough  to 
machine  readily.  About  40  per  cent,  scrap  was  used 
in  a  mixture  of  coke  and  charcoal  pig  iron,  melted  in 
a  cupola.  The  fluidity  strips  ran  up  full.  The  chill 


FORM  OF  CHILL  TESTS  FOR  THE  A.  F,  A0  563 


FIG.   147.  — FKACTURE   OF   CHILL  TEST   PIECES   IN   SERIES   C. 


564 


METALLURGY    OF    CAST    IRON. 


was  merely  perceptible,  as  shown  in  Fig.  147,  page 
563.  This  cast  was  made  under  the  supervision  of  Mr. 
Benj.  D.  Fuller. 

TABLES  D  &  E-IlS. — TESTS  OF  CHILLED    AND    SAND    ROLL  IRON    CAST   AT 
SEAMEN,   SLEETH  ROLL  CO.,   P1TTSBURG,   PA. 


Transverse  test  of  unfinished  green 
sand  bars  in  cast  D. 

Transverse  tests  of  unfinished  green 
sand  bars  in  cast  E). 

a 

ej 

3 

u 

| 

be 
C    ^ 

a 
o 

o 
I 

ti 

<u 

u 

<u 

be 
C    • 

c 

O 

O 

« 

'o 

I 

|l 

d  o 

2 

g 

"8 

V 

a 

xl 

cs  o 

CJ 

u 

2 

0 

3 

j,- 

fl 

c 

o 

Oj 

g.H 

d 

fc 

Q 

« 

« 

o 

fc 

Q 

PQ 

Q 

U 

67 

•54 

280 

.225 

75 

•57 

480 

.280 

68 

1.14 

2,460 

.280 

76 

1.  12 

2,310 

•215 

•  17 

69 

1.74 

ii,  880 

.270 

77 

i-73 

7,100 

.180 

70 

2.27 

25,130 

.248 

•15 

78 

2.23 

20,650 

.190 

.16 

7i 

2-79 

48,650 

.220 

.14 

79 

2-93 

44,200 

.180 

•15 

72 

3-39 

84,200 

.2OO 

.12 

80 

3.26 

61,800 

.190 

.14 

73 

3-'H 

126,360 

.170 

.12 

81 

3-92 

99,280 

.180 

•  13 

74 

4-5° 

201,020 

.l6o 

.11 

82 

4-33 

128,980 

.150 

.12 

The  iron  for  cast  D  was  used  for  heavy  chilled  rolls, 
made  from  a  mixture  of  cold  blast  charcoal  pig  iron 
melted  in  an  air  furnace.  Transverse  bars  were  cast 
only,  for  the  D  and  E  casts,  as  no  data  of  commercial 
value  could  be  obtained  from  tensile  tests  owing  to  the 
metal  being  all  white  in  the  sections  falling  within  the 
scope  of  ordinary  testing  machines;  in  fact,  the 
fractures  of  the  chill  test  pieces  of  the  pattern  shown 
in  Figs.  145  to  147  were  white  all  the  way  through. 
The  fluidity  strips  ran  up  full,  showing  good  hot  iron. 
The  contraction  ranged  from  .  28  in  the  yz  -inch  bar  down 
to  .  1 1  in  the  4-inch  bar.  The  smaller  bars  of  the  D 
and  E  cast  were  tested  by  the  Pittsburg  Testing 
Laboratory,  and  the  heavy  ones  by  the  Riehle  Brothers 
Testing  Machine  Co.,  Philadelphia,  Pa. 


COMPILATION  OF  THE  A.  F.  A.    TESTS,    ETC. 


56S 


TABLE  F-IIQ. — TESTS    OF    SASH 
WEIGHT   IRON.* 


Transverse  tests  of  unfinished 
green  sand  bars.* 


The  iron  for  cast  E  was  used  for  making  sand  rolls 
and  is  of  a  class  similar  to  Cast  D,  and  must  resist 
great  bending  strains  and  sudden  heating  of  their  sur- 
faces. The  iron  used  was  warm  blast  charcoal,  melted 
in  an  air  furnace.  Though  the  fluidity  strips  ran  up 
full,  some  of  the  small  bars  were  lost  owing  to  the  fact 
that  such  iron  chilled  quickly  in  a  molten  state.  The 
chilled  test  pieces  were  white  throughout  the  body, 
the  same  as  with  Cast  D.  The  contraction  ranged 
from  .  1 8  in  i -inch  bars  to  .  1 1  in  4-inch  bars.  This  cast 
was  made  under  the  supervision  of  Mr.  J.  S.  Seamen. 

The  iron  used  for  cast 
F  consisted  of  shop  scrap 
mixed  with  old  grate  bars, 
rusty  thin  malleable 
scrap,  and  a  white  weak 
pig  iron,  melted  in  a 
cupola.  The  mixture 
gave  a  perfectly  white 
fracture  up  to  the  2^- 
inch  sections,  and  slightly 
mottled  in  the  center  of 
the  large  bars.  It  was 
impracticable  to  machine 
this  iron,  and  hence  no 
such  tests  are  shown.  The 
fluidity  strips  did  not  run  up  full,  showing  the  effect 
of  oxidized  iron,  the  chill  extending  throughout  the 
whole  casting  of  the  test  pieces.  The  contraction 
ranged  from  .28  in  the  ^-inch  bars  down  to  .n  in  the 
4-inch  bars. 

*This  cast  and  those  seen  at  G,  H,  I,  J,  K,  and  L,  pages  566  to 
569,  were  made  tinder  the  supervision  of  Dr.  Richard  Moldenke , 
at  the  Pennsylvania  Malleable  Co.  's  foundry,  Pittsburg,  Pa. 


G 

1 

5 

be 

1 

0 
tJ 

u 

eg 

o 

a 

cs  b 

CC 

i 

Q 

w 

Q 

o 
O 

83 

•55 

170 

.085 

29 

84 

1-13 

2,760 

.085 

26 

85 

1.69 

6,270 

.062 

20 

86 

2-15 

15,480 

.060 

87 

2.81 

35,900 

•035 

16 

88 

3-40 

54,420 

.027 

H 

89 

3-98 

72,870 

.025 

12 

90 

4-51 

86.420 

.020 

.11 

566 


METALLURGY    OF    CAST    IRON. 


TABLE  G-I2O. — TESTS    OF    CAR    WHEEL   IRON. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  finished 
green  sand  bars.* 

Tensile  tests  of  unfin- 
ished and  finished 
green  sand  bars. 

No.  of  test. 

Diameter. 

Breaking 
load. 

Deflection. 

! 
•s 

g 

Diameter. 

Breaking 
load. 

Deflection. 

In 
0 

•3 

i 

Diameter. 

Breaking 
load. 

9i 

•54 

420 

.130 

99 

.56 

370 

.200 

106 

•55 

7,440 

92 

1-13 

2,45° 

•125 

100 

1-13 

2,040 

.205 

107 

I.I3 

26,830 

93 

1.69 

7,290 

.110 

101 

1.69 

6,57o 

.170 

108 

1.71 

44,  ioo 

94 

2.14 

14,880 

.100 

102 

2-15 

12,440 

.140 

109 

2.27 

62,760 

95 

2.84 

27,020 

.097 

I03 

2.82 

24,900 

.150 

*Fin 

shed 

iars. 

96 

3-38 

47,810 

.080 

104 

3.38 

44,i3o 

.130 

no 

.56 

6,770 

97 

3-97 

70,550 

.080 

105 

3-95 

60,050 

.120 

in 

1-13 

24,480 

98 

4-50 

86,100 

.070 

112 

1.70 

40,060 

The  iron  used  for  cast  Q  is  such  as  was  intended  to 
resist  abrasion  and  sudden  increase  of  temperature  on 
its  surface,  and  also  to  be  a  good  chilling  iron.  The 
mixture  contained  cold  and  warm  blast  charcoal  pig 
iron,  some  coke  pig  iron,  steel  scrap,  and  old  car 
wheels,  melted  in  a  cupola.  Fluidity  strips  ran  up 
full,  and  the  chill  was  about  ^6 -inch  deep  in  the  face 
of  the  chill  test  pieces. 

TABLE  H-I2I. — TESTS  OF  STOVE  PLATE  IRON. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  finished 
green  sand  bars.* 

Tensile  tests  of  unfin- 
ished and  finished 
green  sand  bars. 

tj 
u 

'o 
6 
£ 

Diameter. 

Breaking 
load. 

Deflection. 

1 
* 

6 
£ 

Diameter. 

Breaking 
load. 

Deflection. 

1 

"S 

d 
fc 

Diameter. 

Breaking 
load. 

"3 

.58 

545 

.130 

121 

•56 

450 

.240 

128 

•56 

5,440 

114 

1-15 

2,100 

.  120 

122 

1-13 

i,57o 

.200 

129 

1-13 

14,400 

"5 

1.71 

(>,<)()() 

.120 

123 

1.69 

5,100 

.180 

130 

1.71 

34-930 

116 

2.14 

12,880 

.105 

124 

125 

2-15 

10,660 

•  175 

131 

2.27 

42,770 

117 

2.83 

20,520 

.IOO 

2.82 

iS,74o 

.160 

*Fin 

ished 

bars. 

118 

3-39 

42,360 

.090 

126 

3-38 

,V),,S<><> 

.140 

132 

.56 

5,4oo 

119 

3.98 

<>4.74<> 

.090 

127 

3-95 

55,000 

•  i.i» 

133 

1.  12 

14,920 

I2O 

4-55 

79*450 

.080 

134 

1.69 

30,110 

COMPILATION    OF    THE    A.    F.    A.    TESTS,   ETC. 


The  iron  for  cast  H  was  intended  for  stove  plate  and 
very  light  ornamental  or  plain  castings.  The  fluidity 
strips  ran  tip  full  and  showed  the  finest  impression 
of  mould.  The  mixture  contained  high  phosphorus, 
coke  pig  iron,  and  stove  plate  scrap.  No  chill  was 
seen  in  the  test  piece 

TABLE  1-122. — TESTS  OF  HEAVY  MACHINERY  IRON. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  finished 
green  sand  bars.* 

Tensile  tests  of  unfin- 
ished and  finished 
green  sand  bars. 

No.  of  test. 

Diameter. 

Breaking 
load. 

Deflection. 

1 

•o 

i 

Diameter. 

Breaking 
load. 

Deflection. 

In 
1 

•8 

£ 

Diameter. 

Breaking 
load. 

135 

,58 

39° 

.220 

143 

.56 

300 

.300 

150 

.64 

7,56o 

136 

1-13 

2,490 

.180 

144 

1-13 

2,120 

.270 

151 

1.20 

24,210 

137 

1.70 

7,010 

.140 

MS 

1.69 

6,570 

.240 

I.S2 

I-7I 

25,740 

138 

2.17 

14,  140 

.110 

i46 

2.15 

13,200 

.200 

153 

2.28 

39,660 

139 

2.84 

28,110 

.105 

147 

2.82 

26,440 

.165 

*Fin 

shed 

bars. 

140 

3.38 

42,000 

."'AS 

i48 

3.38 

40,000 

.125 

154 

•56 

4,5io 

141 

3-97 

58,770 

•095 

149 

3-95 

59,190 

.130 

155 

1-13 

14,120 

142 

4.52 

73,400 

.080 

156 

1.69 

24,990 

TABLE  J-I23- — TESTS  OF  CYLINDER  IRON. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  finished 
green  sand  bars.* 

Tensile  tests  of  unfin- 
ished and  finished 
green  sand  bars. 

No.  of  test. 

Diameter. 

Breaking 
load. 

Deflection. 

1 

•8 

d 
fc 

Diameter. 

W) 
a 
3*O 

P 

Deflection. 

"£ 
V 

"8 

i 

Diameter. 

bo 

9  • 
S'S 

$$ 

w 

157 

•55 

420 

.19 

165 

.56 

300 

•19 

172 

•57 

5,970 

158 

i-i5 

2,550 

.18 

166 

1-13 

2,410 

.16 

173 

1.14 

18,580' 

159 

1.72 

5,544 

.16 

167 

1.69 

6,020 

.14 

174 

1.70 

38,300 

160 

2.16 

i4,34'> 

.12 

168 

2-15 

12,880 

.11 

175 

2.27 

62,440 

161 

2.S4 

27,770 

•13 

169 

2.82 

25,300 

.12 

*Fin 

ished 

jars. 

162 

3.38 

50,660 

.11 

170 

3-38 

42,420 

•07 

176 

•56 

5,860 

163 

3-93 

66,240 

.08 

171 

3-95 

64,590 

.06 

177 

1-13 

20,070 

164 

4-51 

78,97° 

•O? 

178 

1.69 

41,920 

568 


METALLURGY    OF    CAST    IRON. 


The  Iron  used  for  cast  I  was  made  of  all-coke  pig, 
mixed  with  machinery  scrap,  and  a  little  scrap  steel, 
melted  in  a  cupola.  The  mixture  was  intended  for 
heavy  machinery  castings.  Fluidity  and  chill  not 
reported. 

The  iron  used  for  cast  J  contained  some  steel  scrap 
and  high  sulphur  pig,  mixed  with  a  No.  i  foundry  coke 
pig  iron,  melted  in  a  cupola.  The  mixture  was  such 
as  was  desired  to  give  a  dense,  even-grained  iron  hav- 
ing high  wearing  qualities,  impervious  to  steam,  air, 
and  ammonia  gases.  The  iron  was  quite  fluid,  and  gave 
a  chill  about  1-16  inch  deep  in  the  face  of  the  test 
pieces. 

TABLE  K-I24. — TESTS  OF  NOVELTY  IRON. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  unfin- 
ished dry  sand  bars.** 

Tensile  tests  of  unfin- 
ished bars  in  green 
and  dry  sand. 

1 

"8 

g 

Diameter. 

Breaking 
load. 

Deflection. 

No.  of  test. 

Diameter. 

Breaking 
load. 

Deflection. 

1 
? 

d 
5 

Diameter. 

Breaking 
load. 

179 

•57 

200 

.14 

**i87 

•56 

240 

•  17 

193 

•57 

5,630 

180 

1-13 

1,860 

.11 

**:88 

MS 

2,080 

•  13 

196 

•15 

17,860 

181 

1.69 

6,000 

.10 

**iS9 

1.68 

5,810 

.11 

197 

.70 

36,820 

182 

2-15 

10,910 

.07 

**I90 

2.17 

",450 

.10 

198 

.27 

51,180 

183 

2.85 

21,030 

.06 

**K)I 

2.84 

21,950 

.10 

**i99 

.60 

6,850 

184 
185 

3-40 
3-96 

39.500 

.07 

**I92 

3-40 

4i,57o 

.07 

**200 

•13 

17,430 

54,660 

.04 

**I93 

3-97 

56,770 

•05 

**2or 

.70 

33,990 

186 

4-53 

70,020 

•03 

**I94 

4-54 

73,5oo 

.04 

**202 

2.26 

45,040 

**  As  there  were  no  tests  of  finished  bars  in  green  sand  in  this  cast,  we  sup- 
plemented them  with  tests  of  unfinished  bars  cast  in  dry  sand,  designated  by 
the  two  stars,  as  above. 

The  iron  used  for  cast  K  was  soft  in  very  thin  sections 
and  also  very  fluid,  and  ran  well.  The  mixture  con- 
tained high  silicon  and  phosphorus  pig  iron,  stove  plate 


COMPILATION    OF    THE    A.    F.    A.    TESTS,    ETC. 


569 


scrap,  and  odds  and  ends  of  light  junk  scrap,  melted 
in  a  cupola.  The  iron  was  intended  for  such  work  as 
locks,  light  hardware,  and  novelty  castings,  which  in- 
cludes light  electrical  supplies.  The  fluidity  strips  ran 
up  full,  and  the  chill  test  pieces  showed  only  a  slight 
evidence  of  a  chilling  effect  beyond  the  closing  up  of 
the  grain. 

TABLE  L-I25. — TESTS  OF  GUN  IRON. 


Transverse  tests  of  unfin- 
ished green  sand  bars. 

Transverse  tests  of  finished 
green  sand  bars.* 

Tensile  tests  of  unfin- 
ished and  finished 
green  sand  bars. 

«j 

<u 

"o 

d 

£ 

Diameter. 

Breaking 
load. 

Deflection. 

1 
•o 

I 

Diameter. 

Breaking 
load. 

Deflection. 

No.  of  test. 

Diameter. 

Breaking 
load. 

203 

•57 

520 

.24 

209 

.56 

460 

•35 

216 

•57 

8,740 

204 

1.14 

3,470 

•i7 

210 

1-13 

3,260 

•3i 

217 

1-15 

30,460 

205 

1.69 

10,530 

•  15 

211 

1.69 

9,710 

.27 

218 

1.70 

5i,49o 

206 

2.18 

22,550 

.14 

212 

2.15 

20,480 

.20 

219 

2.27 

69,950 

207 

2.84 

43,730 

.12 

213 

2.82 

41,190 

•19 

*Finished 

jars. 

208 

340 

75,46o 

.11 

214 

3-3« 

70,77° 

.14 

220 

.56 

8,220 

Two  additional  tests  be- 
yond range  of  machine. 

215 

3-95 

98,640 

.10 

221 

1-13 

3i,33o 

222 

1.69 

47,000 

The  iron  used  for  cast  L  was  a  mixture  of  the  best 
grades  of  charcoal  iron,  and  some  steel  and  furnace 
scrap  iron,  melted  in  an  open -hearth  steel  furnace. 
It  is  a  class  of  iron  that  was  intended  for  cannon  and 
mortars,  special  dies,  and  heavy  machinery  castings 
requiring  good  strength  and  toughness,  with  uniformity 
of  texture  and  dense  granular  structure.  The  iron 
was  very  hot  and  gave  a  chill  of  about  1-16  inch  thick 
in  the  face  of  the  chill  test  pieces. 

Table  126,  next  page,  gives  the  strength  per  square 
inch  and  table  127  gives  the  analyses,  both  of  which  are 
fully  explained  on  page  555. 


57«> 


METALLURGY    OF    CAST    IRON. 


TABLE  126. — TENSILE  STRENGTH  PER  SQUARE  INCH    OF    UNFINISHED  AND 
FINISHED    BARS    IN    TABLES    1 15    TO    125- 


Ap'rox. 
Orig. 
Diam. 

A 

B 

C 

G 

H 

I 

J 

K 

L 

•57 

16,000 

16,205 

18,265 

31,000 

21,760 

23,620 

22,960 

21,650 

33,610 

1.14 

13,700 

15,865 

15-865 

26,560 

14,  _'<><) 

21,850 

18,210 

I7,?40 

29,570 

1.70 

12,520 

I3,H5 

14,170 

19,340 

15,320 

11,290 

16,940 

16,220 

22,680 

2.27 

11,015 

",405 

12,060 

J5.53° 

10,610 

9.78o 

15,490 

12,700 

17,400 

Fin. 
Diam. 

•56 

13,762 

19,000 

17,386 

27,080 

21,600 

18,040 

23,440 

32,880 

1-13 

13,490 

15,375 

M,994 

24,480 

14,920 

14,120 

20,070 

3i,33o 

1.69 

12,230 

12,525 

n,570 

17,810 

13,580 

11,100 

18,630 

20,890 

TABLE  127. — CHEMICAL    ANALYSES  OF  MIXTURES  A  TO  L, 
TABLES  115  TO  125-*** 


u 

HI 

Class  of  Iron. 

Silicon. 

Sulphur. 

Manganese. 

Phosphorus. 

d 

C.  Carbon. 

T.  Carbon. 

At 

Ingot  mold  

1.67 

•032 

.29 

•095 

3-44 

•43 

3-87 

B 

Dynamo  frame  

i-95 

.042 

•39 

•4°5 

3-23 

•59 

3.82 

C 

Light  machinery... 

2.04 

.044 

•39 

.578 

:.S-> 

•32 

3-84 

D 

Chilled  roll  

•85 

.070 

•  15 

.482 

.06 

2.30 

2.36 

E 

Sand  roll  

.72 

.070 

.17 

•454 

None. 

3-04 

3-04 

n 

Sash  weight  

.91 

.218 

.2\ 

.441 

.20 

2.51 

2.71 

G 

Car  wheel  

•97 

.060 

.40 

.301 

3-43 

•74 

4.17 

H 

Stove  plate  

3-19 

.084 

•38 

1.160 

3.08 

•33 

3-41 

I 

Heavy  machinery.. 

1.96 

.081 

.48 

•522 

2-99 

•33 

3-32 

J 

Cylinder  

2.49 

.084 

•47 

•839 

2-99 

.40 

3-39 

K 

Novelty  

4.19 

.080 

•67 

1.236 

2.85 

•03 

2.88 

L 

Gun  metal  

1.32 

•044 

•43 

.676 

2.62 

•50 

3-12 

f  All  pig  iron.        J  Nearly  all  burnt  scrap. 

***The  above  analyses  of  Table  127  were  determined  from  drillings  ob- 
tained from  i"  square  dry  sand  bars,  taken  from  the  respective  casts. 


SUMMARY  OF    RESULTS  OF  THE   A.  F.  A. 
SERIES  OF  TESTS. 

A  peculiarity  between  transverse  and  tensile  tests 

which  the  A.  F.  A.  series  of  tests  displays,  lies  in  an 
increase  of  transverse  strength  per  square  inch,  and  a 
decrease  of  tensile  strength,  in  opposite  directions, 
according  as  areas  of  cross  sections  are  enlarged.  For 
illustration,  take  the  unfinished  bar,  test  No.  2,  Table 
115,  page  558,  which  is  1.20  diameter,  giving  an  area 
of  1.13  inches,  and  compare  its  strength  per  square 
inch  in  an  approximate  way  with  test  No.  8,  which  has 
an  area  of  16.90  inches,  and  we  find  that  the  larger 
body  has  5 2. 7  per  cent,  greater  strength  per  square 
inch  of  cross  section  or  area  than  the  smaller  body. 
In  the  case  of  tensile  tests,  we  find,  by  an  examination 
of  Table  126,  opposite  page,  that  an  average  of  all  the 
1.14  diameter  unfinished  bars  gave  57,250  pounds 
greater  strength  per  approximate  square  inch  than  an 
average  of  the  2.27  diameter  unfinished  bars.  Were 
the  bars  larger  than  2.27  diameter,  we  would  find  the 
same  principle  to  hold  good. 

The  results  show  that  in  the  construction  of  ma- 
chinery, etc.,  we  may  expect  greater  strength  per 
square  inch  in  transverse  strains  and  less  in  tensile, 
as  areas  of  cross  sections  are  enlarged,  and  further 
demonstrate  that  cast  iron  castings  are  best  con- 
structed to  stand  transverse  strains.  Why  it  is  that 
the  reverse  of  results  should  be  obtained  between 
transverse  and  tensile  tests  as  shown  is  largely  due 
to  the  principle  "in  union  there  is  strength,"  being 
applicable  to  transverse  and  not  to  tensile  strains. 


572  METALLURGY    OF    CAST    IRON. 

However,  if  any  one  should  cut  a  4^ -inch  square 
bar  of  gray  iron  into  i-inch  square  sections,  they 
would  find  that  any  one  of  the  sections  would  then 
stand  a  much  less  transverse  or  tensile  load  than  bars 
of  the  same  area  that  had  been  cast  i  inch  square  of 
the  same  iron. 

It  was  a  current  impression  that  a  large  body  of 
cast  iron  is  weaker  in  strength  per  square  inch  than 
small  ones  of  the  same  grade  or  cast.  We  find  by  a 
study  of  Tables  115  to  126  that  this  is  true  only  in  the 
case  of  tensile  strains.  This  is  the  first  time  that  the 
author  knows  of  attention  being  called  to  this  fact,  and 
now  that  such  is  publicly  done  herein  it  will  result,  no 
doubt,  in  changing  many  practices  that  have  been  fol- 
lowed, based  on  the  supposition  that  in  the  same  iron 
large  bodies  were  weaker  in  strength  per  square  inch 
than  small  ones. 

The  difference  between  the  strength  of  finished  and 
unfinished  bars,  as  shown  by  the  A.  F.  A.  tests, 
demonstrates  that  where  the  same  thickness  of  iron  is 
removed  in  finishing  test  bars,  finished  bars  are  less 
erratic  in  recording  strength  tests  than  unfinished 
bars,  and  that  as  a  rule  finished  bars  are  weaker  than 
unfinished  ones  of  the  same  iron.  A  finished  bar  that 
will  prove  stronger  than  an  unfinished  one  would  gen- 
erally be  due  to  the  outer  surface  body  holding  the 
combined  carbon  higher  than  was  best  for  strength  in 
that  grade  of  iron.  This  generally  occurs  only  in  bars 
that  give  a  great  strength  in  an  unfinished  as  well  as 
finished  state.  To  show  the  difference  between  unfin- 
ished and  finished  bars,  to  make  an  approximate  com- 
parison, seven  tests,  A,  B,  C,  G,  H,  I,  and  J  of  the 
1.70  diameter  unfinished  bars  and  seven  tests  of  the 


SUMMARY  OF   RESULTS  OF  THE  A.  F.  A.    TESTS.  573 

1.69  diameter  finished  bars  (Table  126,  page  570). 
some  casts  having  a  difference  of  only  .01  diameter, 
show  5,380  pounds  or  5.25  per  cent,  less  tensile 
strength  than  the  unfinished  bars.  Carrying  this  to 
transverse  tests,  in  calculating  the  difference  of  fifty 
tests  of  each  class  in  similar  sizes  of  bars,  we  find  that 
the  finished  bars  were  212,000  pounds  or  16.2  per  cent, 
weaker  than  the  unfinished  bars.  The  hard  grades 
show  a  greater  difference  than  the  soft  grades  in  this 
respect.  Of  all  the  transverse  tests  in  Tables  115  to 
126  there  are  only  about  six  finished  bars  that  show 
a  greater  strength  than  their  mates  in  the  unfinished 
bars.  The  ^-inch  bars  are  ignored  in  all  the  com- 
putations because  of  their  unreliability,  as  proven  by 
the  series  of  A.  F.  A.  and  other  tests. 

The  adaptability  of  different  size  bars  for  compara** 
tive  testing  is  well  demonstrated  by  the  A.  F.  A. 
series  of  tests.  They  strongly  endorse  the  author's 
contention  against  the  use  of  bars  as  small  as  ^  inch 
square  or  round,  and  also  show  that  bars  can  be  too 
large  as  well  as  too  small.  The  committee's  report 
recommends  bars  to  be  no  smaller  than  i^  inches 
diameter  and  not  larger  than  2^  inches,  and  all  bars 
to  be  cast  on  end,  which  is  another  point  originally 
and  strongly  advocated  by  the  author.  These  recom- 
mendations are  seen  on  pages  575  and  583.  For  several 
years  the  author  has  realized  from  experience  in  test- 
ing that  a  i  yz  -inch  diameter  bar  was  about  as  small  as 
should  be  used  where  the  best  records  are  desired  in 
gray  irons,  but  he  accepted  the  i^-inch  diameter  bar 
shown  in  other  parts  of  this  work  for  testing,  on 
account  of  its  being  of  an  area  the  most  used  in  the  past 
to  meet  the  general  conditions  of  founders  whp 


574 


METALLURGY    OF    CAST    IRON. 


possess  small  testing-  machines,  and  are  not  that  far 
from  the  best  but  that  they  can  in  some 
cases  be  utilized  in  giving  enough  ap- 
proximate comparative  data  of  cast  iron, 
as  is  shown  in  Chapters  XLIV.,  LX. 
and  LXIX. 

The  utility  of  the  A.  F.  A.  tests  is 
not  confined  to  the  summary  given  in 
this  chapter.  There  are  other  qualities 
which  their  wide  range  of  tests  offer  for 
study  in  obtaining  valuable  knowledge 
that  can  be  utilized,  in  some  special 
instances,  to  assist  any  in  the  best 
practice  of  making  mixtures  of  iron, 
grading  castings,  and  testing  which 
they  set  forth.  As  the  tests  were 
originally  obtained  chiefly  to  derive 
knowledge  of  what  is  best  to  suggest 
for  standardizing  the  testing  of  cast  iron,  we  will  now 
present  an  extract  of  the  A.  F.  A.  committee's  final 
report  as  tendered  by  the  chairman,  Dr.  Richard  Mol- 
denke,  who  is  also  secretary  of  the  association. 

AN   EXTRACT   OF   THE    A.  F.  A.    COMMITTEE'S   REPORT 
ON  STANDARDIZING  THE  TESTING  OF  CAST  IRON. 

Your  committee  desires  to  state  that  during  the  past 
year  (1900)  sufficient  work  has  been  done  to  warrant  a 
final  report,  based  upon  the  results  obtained  and  the 
conclusions  derived  therefrom.  The  magnitude  of  the 
operations  was  fully  realized  at  the  inception  of  the 
plan  (in  1897),  but  it  was  held  that  the  necessities  of 
our  industry  on  the  one  side,  and  the  constantly  grow- 
ing demands  from  buyers  on  the  other,  fully  warranted 


FIG.  148. 


THE    A.    F.    A     COMMITTEES    REPORT.  575 

every  effort  of  time  and  trouble  given  to  this  impor- 
tant subject  so  vital  to  our  existence.  All  of  the 
members  of  your  committee  are  active  foundrymen, 
heavily  burdened  with  responsibilities  which  leave 
little  leisure  for  the  more  interesting  pursuits  of  indus- 
trial science,  yet  ac  little  time  as  possible  was  lost, 
and  only  those  investigations  postponed  which  were 
not  actually  required  for  the  purposes  of  this  report. 

We  must  therefore  beg  that  our  report  be  received, 
and  our  committee  on  standardizing  the  testing  of  cast 
iron  be  discharged.  And  we  further  beg  that  permis- 
sion be  granted  to  the  individual  members  of  our 
committee  to  utilize  the  mass  of  material  collected,  for 
further  investigations  of  interest  to  the  foundry  trade, 
and  the  publication  of  such  results  as  part  of  the  pro- 
ceedings of  this  association. 

Throughout  the  whole  line  of  operations  only  regu- 
larly constituted  mixtures  were  used,  the  balance  of 
the  heats  from  which  these  test  bars  were  cast  going 
directly  into  commercial  castings  of  the  classes  desig- 
nated. The  results  are  therefore  entirely  comparable 
with  daily  practice,  and  are  not  exceptional  cases 
prepared  specially  for  a  good  showing.  For  purposes 
of  comparison  green  sand  and  dry  sand  bars  were 
made  side  by  side,  even  though  the  iron,  in  practice, 
goes  into  only  one  of  these  classes  of  moulds.  It  was 
felt  that  comparison  records  were  wanted  just  as  much 
as  specifications  for  the  separate  lines  of  product.  For 
this  reason  also,  we  recommend  one  standard  size  of 
test  bar  for  comparative  purposes  only,  each  class  of 
iron  being  given  its  special  treatment  for  the  informa- 
tion wanted  in  daily  practice,  in  addition. 

Our  studies  on  the  shape  of  the  test  bar  have  resulted 


576  METALLURGY    OF    CAST    IRON. 

in  the  selection  of  the  round  form  of  cross  section,  a«nd 
this  mainly  on  the  score  of  greatest  uniformity  in 
physical  structure,  the  corners  of  the  square  bar  intro- 
ducing elements  which  become  troublesome.  It  is 
fully  realized  that  the  work  of  testing  bars,  especially 
transversely,  is  made  more  difficult  by  the  adoption  of 
the  round  bar ;  but,  after  all,  this  should  only  mean  the 
taking  of  proper  precautions  in  measuring  the  actual 
net  deflection  —  that  is,  deducting  the  upper  and  lower 
indentations  in  the  bar  by  the  knife  edges,  as  ascer- 
tained by  micrometer  measurement,  from  the  deflection 
record. 

There  is  still  a  further  point  of  interest  in  the 
preparation  of  test  bars,  and  that  is  the  making  of 
coupons  from  which  the  quality  of  the  casting  to  which 
they  are  attached  is  to  be  judged.  This  method  is 
used  extensively  in  government  work  and  in  the  mak- 
ing of  cylinder  castings.  The  idea  of  obtaining 
material  from  the  same  pour  in  the  same  mould  as 
part  of  the  casting  itself  is  good  enough  in  theory. 
Unfortunately,  however,  this  direct  connection  intro- 
duces elements  of  segregation  and  temperature  changes 
in  the  cast  iron  which  make  this  test  less  valuable  than 
is  generally  supposed.  At  best,  the  iron  which  has 
passed  through  the  different  parts  of  a  mould  before 
entering  the  space  for  the  coupon  will  not  be  repre- 
sentative of  the  whole  body,  but  rather  one  portion  of 
it  only.  We  therefore  recommend  the  method  shown 
later  on  in  Fig.  149.  The  metal  can  ^ be  poured  from 
crane  or  hand  ladle  clean  and  speedy,  and  possesses 
the  temperature  of  the  average  iron  in  the  casting  more 
nearly  than  the  coupon  method  now  practiced. 

Your  committee,  while  giving  specifications  for  the 


THE    A.    F.    A.    COMMITTEE  S    REPORT.  577 

tensile  test  of  cast  iron,  is  of  the  opinion  that  the 
transverse  test  is  the  more  desirable,  and  certainly 
within  reach  of  even  the  smallest  foundry.  '  We 
further  would  suggest  to  the  mechanical  engineers  of 
this  country  the  desirability  of  standardizing  the  speed 
at  which  the  various  tests  should  be  performed,  and 
also  the  urgent  necessity  of  studying  the  impact  test 
in  its  various  phases.  We  deem  these  questions  out- 
side of  the  province  of  this  association,  our  work  being 
the  selection  of  methods  for  getting  at  the  true  value 
of  the  material  we  sell,  without  prejudice  or  favor. 

In  selecting  the  test  bars  for  the  purpose  of  specifi- 
cation, we  have  followed  the  cardinal  principle  of 
selecting  the  largest  cross  section  for  the  iron  consist- 
ent with  a  sound  physical  structure,  and  within  the 
range  and  structural  limits  of  an  ordinary  testing 
machine.  The  following  are  the  sizes  of  bars  selected 
for  tests  as  a  result  of  our  investigations : 

For  all  tensile  tests  a  bar  turned  to  .  8  inch  in  diam- 
eter, corresponding  to  a  cross  section  of  y2  square 
inch.  Results,  therefore,  multiplied  by  two,  give  the 
tensible  strength  per  square  inch. 

For  transverse  test  of  all  classes  of  iron  for  general 
comparison,  a  bar  i  ^  inches  diameter,  on  supports  1 2 
inches  apart,  pressure  applied  in  middle,  and  deflection 
noted.  Similarly  for  light  machinery,  stove  plate, 
and  novelty  iron  a  i^-inch  diameter  bar;  that  is  to 
say,  for  irons  running  from  2  per  cent,  in  silicon 
upward,  or  from  1.75  per  cent,  silicon  upward  where 
but  little  scrap  is  in  the  mixture. 

For  dynamo  frame,  cylinder,  heavy  machinery,  and 
gun  metal  irons,  similarly  a  2 -inch  diameter  bar  is 
recommended;  that  is,  for  irons  running  from  1.50  to 


578 


METALLURGY    OF    CAST    IRON. 


FIG.    149. 

Plan  and  Elevation  View  of  Casting  a  few  Tensile  and  Transverse  Test 
Bars  on  end,  at  one  pouring. 


THE   A.  F.  A.     COMMITTEE  S    REPORT. 


579 


2  per  cent,  in  silicon,  or  where  the  silicon  is  lower  and 
the  proportion  of  scrap  is  rather  large. 

For  roll  irons,  whether  chilled  or  sand,  and  car  wheel 
metals,  a  2^ -inch  diameter  bar  is  recommended;  that 
is,  for  all  irons  below  i  per  cent,  silicon,  and  which 
may  therefore  be  classed  as  the  chilling  irons.  This 
would  include  also  all  white  irons. 

The  method  of  moulding  the  test  bars  we  would 
recommend  is  given  herewith,  and  is  such  as  will 
be  readily  understood  by  every  practical  foundryman. 
Both  tensile  and  transverse  bars  are  shown  in  the  same 
flask.  The  elevation  shows  the  tensile  bar  at  A  and 
the  transverse  one  at  B.  The  core  C  is  used  with  the 
tensile  bar  in  order  to  ram  it  on  end.  The  core  box  is 
seen  at  Fig.  150.  In  starting  to  mould  up  the  bars  the 
dried  core  is  set  on  the  bottom  board,  and  then  the 
pattern  as  seen  at  D  placed  into  the  hole  in  the  top  of 


FIG.    ISO.— CORE  BOX,  TENSILE  TEST  PATTERN. 

the  core  and  let  rest  on  its  bottom.  Now  ram  up  the 
bar  with  green  sand  in  the  usual  manner.  The  plan 
shows  four  bars.  This  can  be  modified  as  desired. 
If  no  tensile  bars  are  wanted,  the  core  is  avoided 
altogether.  Two  bars  may  be  poured  at  a  time,  or 
four,  or  more,  by  simply  connecting  the  pouring  basin 
E  E  as  shown  by  the  dotted  line  around  G,  in  which 
case,  however,  the  basin  E  E  should  be  made  much 
smaller.  At  least  three  bars  of  a  kind  should  be  made 
for  a  given  test.  The  accompanying  sketches  give  all 


580  METALLURGY    OF    CAST    IRON. 

the  necessary  dimensions.  It  will  be  noted  that  the 
bottom  of  the  mould  is  conical,  as  seen  at  I.  This  is  to 
present  a  sloping  surface  to  the  dropping  iron  and 
help  to  avoid  its  cutting  the  bottom  of  the  mould. 

These  bars  could  be  moulded  flat  and  poured  on 
their  ends  by  arranging  the  flask  in  such  a  manner  that 
pouring  gates  and  basins  can  be  provided  on  top. 
The  extra  labor  of  carrying  out  this  method,  in  a 
measure  counterbalances  the  making  of  the  core  C. 
The  only  advantage  of  moulding  flat  lies  in  the  greater 
certainty  of  obtaining  bars  free  from  swells  when  made 
by  inexperienced  moulders. 

The  sand  should  not  be  any  damper  than  to  mould 
well  and  stand  the  wash  of  the  iron  without  cutting, 
blowing,  or  scabbing.  It  should  be  rammed  evenly 
to  avoid  swells,  and  poured  by  dropping  the  metal 
from  the  top  through  gates  or  from  the  ladle  direct 
into  the  open  mould.  If  the  sand  will  not  stand  pour- 
ing from  the  top,  then  pour  from  the  bottom  by 
means  of  whirl  gates.  If  there  are  more  than  four 
bars  to  be  poured  from  the  same  ladle  of  iron,  where 
it  would  take  more  than  two  minutes'  time  in  pour- 
ing, they  should  be  gated  so  that  the  one  pouring 
basin  can  fill  all  the  gates  at  about  the  same  time,  thus 
insuring  all  bars  in  a  set  having  the  same  temperature 
of  pouring.  After  the  bars  are  cast  they  should  remain 
in  their  moulds  undisturbed  until  cool. 

PROPOSED     STANDARD     SPECIFICATIONS     FOR     GRAY 

IRON    CASTINGS    AND    TEST    BARS,    AS 

ADOPTED    BY    A.  F.  A. 

i.  Unless  furnace  iron  or  subsequent  annealing  is 
specified,  all  gray  iron  castings  are  understood  to  be  of 


THE 
THE  A.  F.  A.   COMMITTEE'S  REPORT. 


cupola  metal;  mixtures,  moulds,  and  methods  of 
preparation  to  be  fixed  by  the  founder  to  secure  the 
results  by  purchaser. 

2.  All   castings   shall   be   clean,    free   from    flaws, 
cracks,  and  excessive  shrinkage.     They  shall  conform 
in  other  respects  to  whatever  points  may  be  specially 
agreed  upon. 

3.  When  the  castings  themselves  are  to  be  tested 
to  destruction,  the  number  selected  from  a  given  lot 
and  the  tests  they  shall  be  subjected  to  are  made  a 
matter   of   special   agreement    between   founder    and 
purchaser. 

4.  Castings    made  under  these    specifications,   the 
iron  in  which  is  to  be  tested  for  its  quality,  shall  be 
represented  by  at  least  three  test  bars  cast  from  the 
same  heat. 

5.  These  test  bars  shall  be  subjected  to  a  transverse 
breaking  test,  the  load  applied  at  the  middle  with  sup- 
ports 1 2  inches  apart.     The  breaking  load  and  deflec- 
tion shall   be   agreed   upon  specially  on   placing  the 
contract,  and  two  of  these  bars  shall  meet  the  require- 
ments.* 

6.  A  tensile  strength  test  may  be  added,  in  which 
case  at  least  three  bars  for  this  purpose  shall  be  cast 
with  the  others  in  the  same  moulds  respectively.     The 
ultimate  strength  shall  also  be  agreed  upon  specially 
before  placing  the  contract,  and  two  of  the  bars  shall 
meet  the  requirements. 

*  NOTE.—  The  remarkably  wide  range  or  values  for  the  ultimate 
strength  and  modules  of  rupture  which  are  really  good  for  the 
various  classes  of  iron,  precludes  the  giving  of  definite  upper 
limits  in  the  specifications.  It  will  therefore  remain  a  matter  of 
mutual  agreement  in  each  case,  the  requirements  of  service  and 
price  per  pound  paid  regulating  the  mixtures  which  can  be  used. 


THE   A.  F.  A.  COMMITTEE  S   REPORT. 


583 


[i ,,14- 

FIG.  152. — STEEL  SOCKET  FOR  TENSILE  TEST  OF  CAST  IRON. 

Two  required.    Test  pieces  should  fit  in  loosely. 


FIG.   153. — STANDARD  TEST   BAR  FOR  CAST  IRON. 
Cross  Section  equals  %  square  inch. 

7.  The  dimensions  of  the  test  bars  shall  be  as  given 
herewith.     There  is  only  one  size  for  the  tensile  bar 
and    three    for    the    transverse.     For   the   light   and 
medium  weight  of  gray  iron  castings  the   i^-inch  D 
bar  is  to  be  used,  for  heavy  gray  iron  castings  the 
2 -inch  D,  and  for  chilling  irons  the  2^ -inch  D  test  bar. 
These  bars  are  seen  in  Figs.  151,  152,  and  153. 

8.  Where  the  chemical  composition  of  the  castings 
is  a  matter  of  specification  in  addition  to  the  physical 
testsx  borings  shall  be  taken   from   all  the  test  bars 
made,    well  mixed,   and  any  required    determination, 
combined  carbon  and  graphite  alone  excepted,   made 
therefrom.  * 

*NOTE. — There  should  really  be  no  necessity  for  this  test,  for 
the  requirements  of  the  physical  tests  presuppose  a  given  chem- 
ical composition.  It  may,  however,  sometimes  be  expedient  to 
know  the  total  carbon,  silicon,  sulphur,  manganese,  and  phos- 
phorus of  a  casting  to  insure  good  service  conditions. 


584  METALLURGY    OF    CAST    IRON. 

9.  Reasonable  facilities  shall  be  given  the  inspec- 
tors to  satisfy  themselves  that  castings  are  being 
made  in  accordance  with  specifications,  and,  if  pos- 
sible, tests  shall  be  made  at  the  place  of  production, 
prior  to  shipments. 

These  somewhat  general  specifications  are  doubt- 
less capable  of  being  modified,  but  are  presented  by 
us  to  this  Association  for  discussion  and  possible 
approval  in  lieu  of  anything  better  now  in  existence.* 
The  specifications  should  certainly  be  fair  to  con- 
sumer and  founder,  and,  if  experience  teaches  us 
better,  can  be  suitably  modified  from  time  to  time. 

From  the  first  outline  of  our  plan  of  casting  test 
bars,  now  known  so  generally,  to  the  final  completion 
of  this  report  we  have  endeavored  to  obtain  informa- 
tion valuable  to  our  industry,  and  sincerely  hope  that 
much  good  may  result  from  this,  we  think,  impartial 
series  of  conclusions.  Respectfully, 

DR.  RICHARD  MOLDENKE, 
THOS.  D.  WEST, 
JAS.  S.  STIRLING, 
Jos.  S.  SEAMAN, 
Jos.  S.  MCDONALD. 

*  This  report  and  specifications  were  received  and  unanimously 
adopted  by  the  A.  F.  A.  Convention  at  Buffalo,  June,  1901.  The 
committee  was  tendered  a  vote  of  thanks  and  was  discharged. 


CHAPTER  LXXI. 

NEW  PROCESS  FOR  BRAZING  CAST  IRON. 

In  the  •« American  Machinist"  of  March  14,  1901,  an 
editorial  appears  on  this  subject  in  which  it  says:  "  If 
the  reports  of  the  extreme  ease  with  which  this  pro- 
cess is  applied  and  of  its  successful  results  are  well 
founded,  its  discovery  marks  an  important  epoch  in 
metal  working.  It  was  invented  by  an  engineer  named 
Poech,  and  has  been  thoroughly  tested  at  the  Mechan- 
ical Technical  Testing  Institute  at  Charlottenburg, 
near  Berlin.  Professor  Martens,  of  this  institute,  testi- 
fies that  the  iron  thus  brazed  stands  the  strain  like 
new  and  has  not  deteriorated  under  the  process.  The 
discovery  has  already  been  applied  by  a  number  of 
prominent  engineering  firms  in  Great  Britain. 

«*This  method  of  brazing  is  explained  as  follows: 
After  the  surfaces  have  been  cleaned,  they  are  treated 
with  a  moistened  mixture  of  *  ferrofix  '  (which  is  the 
term  applied  by  the  inventor  to  a  metallic  oxide,  pref- 
erably of  copper)  and  a  flux  such  as  borax,  soluble 
glass,  or,  better,  '  borifix, '  a  mixture  recently  invented 
and  patented  by  the  same  inventor.  The  surfaces  are 
well  covered  with  borax  or  borifix,  then  with  strong 
solder  such  as  is  used  for  wrought  iron,  and  then  the 
metal  is  brought  to  a  red  heat.  A  chemical  decompo- 
sition takes  place  in  which  the  oxygen  of  the  metallic 
oxide  combines  with  the  carbon  of  the  iron  to  form 


586  METALLURGY    OF    CAST    IRON. 

volatile  carbonic  acid  or  carbonic  oxide,  setting  free 
pure  metal.  This  metal  covers  the  surfaces  of  the 
iron  intimately,  filling  the  smallest  pores,  and  facilitates 
the  direct  and  intimate  union  of  the  solder  with  the 
iron.  The  flux  that  has  been  added  covers  the  place 
of  the  brazing  with  a  vitreous  skin,  which  pre- 
vents the  oxidation  of  the  iron  and  the  soldering 
metal. 

"  The  avenues  of  utility  suggested  for  the  new  proc- 
ess are  three:  First,  repairing  cast  iron;  second, 
putting  together  large  castings  (which  may  be  made 
in  sections  to  facilitate  moulding  and  transportation) ; 
third,  brazing  cast  iron  to  other  metals.  In  this  way 
cast  iron  can  be  used  in  places  where  wrought  iron  or 
steel  is  now  employed,  by  making  only  that  part  out 
of  the  stronger  metal  which  is  exposed  to  special 
strain.  While  it  is  hardly  to  be  expected  that  all  pieces 
can  be  brazed  with  equal  success,  it  is  stated  that  a  gear 
wheel  40  inches  in  diameter  and  weighing  about  220 
pounds  has  been  satisfactorily  repaired  in  six  places  in 
hub,  spokes,  and  crown.  Moreover,  bars  4  inches  in 
diameter  which  have  been  thus  brazed  and  then  broken 
at  the  same  place  with  a  chisel,  showed  a  new  line  of 
rupture.  It  is  not  known  that  '  ferrofix '  has  yet 
reached  America,  but  it  can  be  obtained  in  Germany 
from  Rodolphe  Winnike  of  Berlin.  It  is  also  being 
introduced  to  the  trade  in  England  from  H.  Bertram  & 
Co.,  28  Queen  street,  London,  E.  C.,  who  offer  to 
supply  full  particulars. ' ' 


ETCHING.* 

Those  who  have  much  to  do  with  chilled  irons  will 
find  the  etching  test  a  valuable  one.  While  the  prac- 
tised eye  alone  can  arrive  at  the  true  valuation  of  what 
the  etched  surface  shows,  yet  the  test  is  so  simple  that 
the  operation  should  be  understood  generally.  The 
greatest  development  has  naturally  been  in  the  line  of 
the  steels.  First,  to  distinguish  between  these  and 
wrought  iron  and  thus  readily  detect  fraud  and  substi- 
tution. Second  and  later,  to  get  at  the  actual  crys- 
talline structure  in  order  to  judge  the  quality  as 
affected  by  the  heat  and  mechanical  treatment  the 
specimens  had  received. 

For  cast  iron,  the  polished  and  etched  surface  shows 
up  the  nature  of  the  crystalline  structure  in  the  chilled 
portion,  and  the  gradation  into  gray  iron.  Where 
experiments  are  made  with  additions  of  steel  or 
wrought  scrap,  the  appearance  of  the  etchings  is 
a  guide  to  the  probable  wearing  qualities.  The  samples 
must  be  first  prepared  by  filing  or  grinding  to  get  a 
flat  surface.  Then  this  is  smoothed  with  successive 
grades  of  emery  cloth  until  a  bright  surface  is  obtained 
which  is  not  too  deeply  scratched.  This  polished  sur- 
face must  not  be  touched  with  the  fingers,  as  anything 
of  a  greasy  nature  prevents  the  acid  from  attacking 
the  iron.  Now  the  piece  is  immersed  face  up  in  nitric 
acid  diluted  with  ten  parts  of  water.  It  is  best  to  use 
this  mixture  cold.  A  few  seconds  will  suffice  to  bring 
out  the  structure.  The  test  piece  is  then  taken  out 
and  washed  thoroughly  in  running  water. 

*  This  article  on  etching  was  contributed  to  this  work  by  the 
kindness  of  Dr.  Richard  Moldenke. 


588  METALLURGY    OF    CAST    IRON. 

If  it  is  desired  to  print  from  the  etching,  more  care 
must  be  taken.  The  specimen  should  be  perfectly 
flat,  —  if  possible,  with  two  parallel  surfaces.  The 
etching  solution  used  is  weaker  —  say  one  nitric  acid, 
and  fifty  or  even  one  hundred  water.  A  small  brush 
can  be  used  to  advantage  to  run  over  the  top  of  the 
specimen  to  remove  the  spent  acid  and  keep  a  good 
circulation.  This  makes  the  etching  process  slow  but 
uniformly  even.  The  result,  however,  is  really  fine, 
and  the  novice  will  do  well  to  practice  on  wrought 
iron,  which  gives  beautiful  etchings.  In  printing 
from  these  etched  specimens  an  ordinary  printer's 
roller,  not  too  heavily  charged  with  ink,  is  used,  and 
the  paper  must  be  a  superfine  calendered  variety  which 
is  perfectly  smooth. 


TABLES  OF  UTILITY  FOR  FOUNDING. 

TABLE    128. — NET    WEIGHT    OF    SAND    PIG   IRON    PER    TON    OK  2,263    LBS. 


Net. 

Gross. 

Net, 

Gross. 

Net, 

Gross. 

i 

2,268 

35 

79.380 

69 

156,492 

2 

4,536 

36 

81,648 

70 

158,760 

3 

6,804 

37 

83.916 

7i 

161,028 

4 

9,072 

38 

86,184 

72 

163,296 

5 

",34o 

39 

88,452 

73 

165,564 

6 

I3,6c8 

40 

90,720 

74 

167,832 

7 

15,876 

4i 

92,988 

75 

170,100 

8 

18,144 

42 

95,256 

76 

172,368 

9 

20,412 

43 

97,524 

77 

174,636 

10 

22,680 

44 

99,792 

78 

176,904 

ii 

24,948 

45 

102,060 

79 

179,172 

12 

27,216 

46 

104,328 

80 

181,440 

13 

29,484 

47 

106,596 

81 

183,708 

14 

31-752 

48 

108,864 

82 

185,976 

15 

34,020 

49 

111,132 

83 

188,244 

16 

36,288 

50 

113,400 

84 

190,512 

17 

38,556 

5i 

115,668 

85 

192,780 

18 

40,824 

52 

"7,936 

86 

195,048 

"i9 

43,09J 

53 

120,204 

87 

I97,3i6 

20 

45,36o 

54 

122,472 

83 

199,584 

21 

47,628 

55 

124,740 

89 

201,852 

22 

49,896 

55 

127,008 

90 

204,120 

23 

52,164 

57 

129,276 

9i 

206,388 

24 

54,432 

58 

131,544 

92 

208,656 

25 

56,700 

59 

133,812 

93 

210,924 

26 

58,968 

60 

136,080 

94 

213,192 

27 

61,236 

61 

138,348 

95 

215,460 

28 

63,504 

62 

140,616 

96 

217,728 

29 

65,772 

«3 

142,884 

97 

219,996 

30 

68,040  • 

64 

145,152 

98 

222,264 

31 

70,308 

65 

147,420 

99 

224,532 

32 

72,576 

66 

149,668 

100 

226,800 

33 

74,844 

67 

151,956 

34 

77,112 

68 

154.224 

590 


METALLURGY    OF    CAST    IRON. 


TABLE  129. — NET  WEIGHT  OF  CHILLED    PTG    IRON  PER  TON    OF    224O  LBS. 


Net. 

Gross. 

Net. 

Gross. 

Net. 

Gross. 

Net. 

Gross. 

I 

2,240 

26 

58,240 

5i 

114,240 

76 

170,240 

2 

4,480 

27 

60,480 

52 

116,480 

77 

172,480 

3 

6,720 

28 

62,720 

53 

118,720 

78 

174,720 

4 

8,960 

29 

64,960 

54 

120,960 

79 

176,960 

5 

11,200 

30 

67,200 

55 

123,200 

80 

179,200 

6 

i3,44o 

3i 

69,440 

56 

125,440 

81 

181,440 

7 

15,680 

32 

71,680 

57 

127,680 

82 

183,680 

8 

17,920 

33 

7-3,920 

58 

129,920 

83 

185,920 

9 

20,160 

34 

76,  160 

59 

132,  160 

84 

188,160 

10 

22,400 

35 

78,400 

60 

134,400 

85 

190,400 

ii 

24,640 

36 

80,640 

61 

136,640 

86 

192,640 

12 

26,880 

37 

82,880 

62 

138,880 

8? 

194,880 

13 

29,120 

38 

85,  120 

'63 

141,120 

88 

197,120 

H 

3i,36o 

39 

87,360 

64 

i43,36o 

89 

199,360 

15 

33,600 

40 

89,600 

65 

145,600 

90 

201,600 

16 

35,840 

41 

91,840 

66 

147,840 

9i 

203,840 

17 

38,080 

42 

94,080 

67 

150.080 

92 

206,080 

18 

40,320 

43 

96,320 

68 

152,320 

93 

208,320 

J9 

42,560 

44 

98,560 

69 

i54,56o 

94 

210,560 

20 

44,800 

45 

IOO,800 

70 

156,800 

95 

212,800 

21 

47,040 

46 

103,040 

7i 

159,040 

96 

215,040 

22 

49,280 

47 

105,280 

72 

161,280 

97 

217,280 

23 

Si.S20 

48 

107,520 

73 

163,520 

98 

219,520 

24 

53,760 

49 

109,760 

74 

165,760 

99 

221,760 

25 

56,000 

50 

112,000 

i  » 

168,000 

IOO 

224,000 

TABLES    OF    UTILITY    FOR    FOUNDING,    ETC. 


591 


TABLE  130.— TABLE   OF    CHEMICAL    SYMBOLS    AND    ATOMIC    WEIGHTS. 
(MEYER   &  SEUBERT.) 


Aluminum,  Al 27.04 

Antimony,  Sb.   .    .    .    .    .119.6 

Arsenic,  As 74.9 

Bismuth,  Bi 207.5 

Bromine,  Br 79. 76 

Cadmium,  Cd.    .    ;  .    .    .111.7 

Calcium,  Ca 39. 91 

Carbon,  C n-97 

Carbon  Graphitic,  C  (Graph.) 
Carbon  Combined, C  (Comb.) 
Carbonic  Acid,  CO2. 
Carbonic  Oxide,  CO. 

Chlorine,  Cl 35-37 

Chromium,  Cr 52.45 

Cobalt,  Co 58.6 

Copper,  Cu 63.18 

Fluorine,  F 19.06 

Ferric  Oxide,  Fe2.  03. 
Ferrous  Oxide,  Fe.  O. 

Gallium,  Ga. 69.9 

Gold,  Au 196.2 

Hydrogen,  H i. 

Iodine,  1 126.54 

Iridium,  Ir 192.5 

Iron,  Fe 55-88 


Lead,  Pb 206.39 

Litharge,  PbO. 

Magnesium,  Mg.    .   .    .    23.94 

Manganese,  Mn.     ...    54.8 

Mercury,  Hg 199.8 

Nickel,  Ni 58.6 

Nitrogen,  N 14.01 

Oxygen,  0 15-96 

Palladium,  Pd 106.2 

Phosphorus,  P 30.96 

Phosphoric  Acid,  ?2.  05. 

Platinum,  Pt 194-3 

Potassium,  K 39-03 

Silicon,  Si 28.0 

Silver,  Ag.        107. 66 

Sodium,  Na 22.995 

Sulphur;  S 31.98 

Tin,  Sn H7-35 

Tungsten,  Wo 183.6 

Uranium,  Ur 239.8 

Vanadium,  V 51.1 

Yttrium,  Y 89.6 

Zinc,  Zn 64.88 

Zirconium,   Zr 90.4 


TABLE  131.— VALUE  IN  DEGREES  CENTIGRADE  FOR  EACH  IOO  DEGREES 
FAHRENHEIT. 


Fahr. 

Cent. 

Fahr. 

Cent. 

Fahr. 

Cent. 

Fahr. 

Cent. 

IOO 

55.56 

IOOO 

555-56 

200O 

IIII.  11 

3000 

1666.67 

200 

in.  ii 

I  IOO 

Oil.  II 

2100 

116667 

3100 

1722  22 

300 

166.67 

1200 

666.67 

2200 

1222.22 

3200 

1777.78 

400 

222.22 

1300 

722.22 

23OO 

1277.78 

3300 

1833.33 

500 

277.78 

1400 

777.78 

2400 

1333  33 

3400 

1888.89 

6co 

333-33 

1500 

833.33 

2500 

1388  89 

35oo 

1944.44 

700 

388.89 

1600 

888.89 

2600 

1444.44 

3600 

2000  00 

800 

444.44 

1700 

944-44 

2700  . 

1500.00 

9  o 

500.00 

1800 

IOOO.OO 

2800 

1555  55 

1900 

1055-55 

2900 

I  oil.  1  1 

"  Absolute  Zero  "  of  the  Air  Thermometer  is  equal— 460°  Fahrenheit. 
"  "  "  "  "  —273.5°  Centigrade. 


592 


METALLURGY    OF    CAST    IRON. 


HEAT  UNITS. 

There  are  three  units  in  use  for  measuring  the  quantity  of  heat 
contained  in  matter. 

The  first  is  the  British  thermal  unit,  and  which  is  the  amount 
of  heat  required  to  raise  i  pound  of  water  i°  Fahrenheit. 

The  second  is  the  thermal  unit,  and  which  is  the  amount  of 
heat  required  to  raise  i  pound  of  water  i°  centigrade. 

The  third  is  the  calorie,  and  which  is  the  amount  of  heat 
necessary  to  raise  i  kilogram  of  water  i°  centigrade. 

The  calorie  is  used  in  Germany,  France  and  other  countries 
using  the  metric  system  of  weights  and  measures. 

TABLE  132.— HEAT   OF    COMBUSTION. 

Heat  developed  by  combustion  of  one  pound  of  the  following 
substances : 


Substance. 

Calories. 

Substance. 

Calories. 

Anthracite 

7  200  to  8  200 

Lignite      

4,500  to  6  ooo 

Alcohol. 

7  !85 

Manganese  to  MnO.. 

1,723 

Carbon  to  CO 

2  404 

Marsh  Gas       

13,063 

Carbon  to  CO2 

8  080 

Olifient  Gas  

ii  858 

Coal    bituminous 

6  500  to  9  ooo 

Olive  Oil.            

9860 

Coke                       ...v.... 

6  400  to  8  ooo 

Petroleum         

10  600  lo  ii  ooo 

Diamond 

7  87Q 

Phosphorus  —  P2O5 

5  747 

Ether 

Silicon 

7  8y> 

tA  462 

Sulphur  to  SO2 

2  162 

Iron  to  KeO 

I  \SI 

Sulphur  803 

2  868 

Iron  to  Kea  03 

I  887 

Wood 

2  500  to  4  ooo 

TABLE  133.— SCALE   OF    TEMPERATURES    BY    COLOR    OF    IRON. 


Dark  red,  hardly  visible    970°  F. 

Dull  red 1300°  " 

Cherry,  dark 14*50°  " 

red 1650°  " 

light     ....    1800°  " 


Orange 2000°  F. 

Yellow 2150°  " 

White  heat 2350°  " 

"      welding     .    .    .  2600°  " 

"       dazzling    .    .    .  2800°  " 


TABLES    OF    UTILITY    FOR    FOUNDING,    ETC. 


593 


TABLE  134.— MELTING    POINTS    OF    METALS. 


Cent. 

Fahr. 

Cent. 

Fahr. 

8so 

i  562 

Iron 

I  SQO 

2  894 

826 

Lead 

626 

266 

511 

Manganese  

l>55° 

2,822 

Cadmium  

321 

610 

Nickel  

I>45° 

2  642 

Cromium 

i  700 

3  ^92 

Palladium  

1,500 

2,732 

Cobalt 

I  WX) 

2  7-12 

Platinum 

i  77S 

•3    227 

Copper          

I  054 

1,929 

Silver  

954 

Gold 

I  147 

2  O97 

Tin  

230 

446 

Iridium..        

I>95° 

3,542 

Zinc  

427 

801 

TABLE  1 3 5.— RELATIVE    CONDUCTIVITY    OF    METALS    FOR    HEAT    AND 
ELECTRICITY. 


Metal  (in  vacuo). 

Heat. 

Elec- 
tricity. 

Metal  (in  vacuo). 

Heat. 

Elec- 
tricity. 

Silver  

IOO. 

100 

Iron 

II  O 

14/44 

Copper  

74- 

77-43 

Steel  

10.3 

Gold  

54  8 

55  J9 

Lead  

7  9 

7  77 

Zinc 

28  i 

27  V) 

Platinum 

Brass  

24  o 

22.  0 

German  Silver... 

6.3 

Tin    

15-4 

11  45 

Bismuth 

i  8 

i  8 

SPECIFIC  GRAVITY  of  a  substance  is  the  ratio  of  the  weight  of 
unit  volume  of  the  substance  to  the  weight  of  the  same  volume 
of  water  at  4°C. 

DENSITY  of  the  substance  is  measured  by  the  number  of  units 
of  mass  in  a  unit  volume  of  the  substance.  • 

TABLE  136.— SPECIFIC    GRAVITY    AND    WEIGHT    PER    CUBIC    INCH — 
METALS. 


Metal. 

Sp.  Grav. 

Weight 
per  cu. 
in.  Ibs. 

Metals. 

Sp.  Grav. 

Weight 
per  cu. 
in.  Ibs. 

Aluminum  
Antimony  

2.56-2.67 
6  71 

.094 

Manganese  

8  01 

.200 
062 

Bismuth  

9  9 

J-2    CQ 

40  1 

Brass  

7.8-88 

Nickel 

&7 

Bronze 

8  7 

Copper;  cast  

8  79 

708 

Copper,  wire  
German  Stiver  

889 

•322 

Platinum,  cast  
Silver  

20.33 
10.5 

yt 

Gold,  hammered... 

19  40 

701 

Sodium 

97 

•°35   • 

Gold,  cast  

IQ  26 

607 

Steel 

7  82 

.281 

Iron,  cast  

7-2O 

260 

Tin      

7  29 

.263 

Iron,  bar  

7  79 

282 

Zinc     

6  86 

.248 

Lead 

594 


METALLURGY    OF    CAST    IRON. 


TABLE  137.  —  ULTIMATE  RESISTANCE  TO  TENSION  IN  POUNDS  PER 
SQUARE  INCH. 


40,000 
54,000 
90,000 


ATerage 
Brass  —  cast  .....................................................  17,000 

wire  ......................................................  48,000 

Copper  —  cast  ...................................................  19,000 

sheet  ...................................................  32,000 

wire  ..................................................  61,000 

Iron  —  cast  .......................................................  10,000  to 

wrought  ..................................................  48,000  to 

wire  .......................................................  70,000  to 

Lead  —  cast  ....................  „  ............  -f  ....................  1,200 

sheet  .....................................................  3,000 

Platinum  —  wire  ..................  .  .............................  53,ooo 

Steel  ...............................................................  60,000  to  120,000 

Tin  —  cast  .......................................................  5,000 

Zinc  .............................  ..................................  7,000  to      8,000 

TABLE  138.  —  TIMBER  (SEASONED). 

Wood'  Average. 

Ash  ..................................................................  16,000 

Beech  ..............................................................  12,000  to    18,000 

Hickory  .....................  .^  ..................................  11,000 

Oak  —  American  ................................................  11,000  to    18,000 

Pine  —        "        white  and  red  ............................  10,000 

Poplar  ..............................................................   7,000 

139.  —  TABLE  OF  DECIMAL  EQUIVALENTS  OF  8THS,    I6THS,   32DS,   AND 
64THS   OF   AN   INCH. 


8ths. 

32ds. 

64ths. 

31-64  =  .484375 

1-8  =  .125 

1-32  =  .03125 

1-64=  .015625 

33-64  =  .515625 

1-4=  .250 

3-32  =  .09375 

3-64  =  .046875 

.35-64  =  .546875 

3-8  =  -375 

5-32  =  .15625 

5-64  =  .078125 

37-64  =  .578125 

1-2  =  .500 

7-32  =  .21875 

7-64=  .109375 

39-64  =  .609375 

5-8  =  .625 

9  32  =  .28125 

9-64  =  .140625 

41-64  =  .640625 

3-4  =  .750 

11-32  =  .34375 

11-64  =  .171875 

43-64  =  .671875 

7-8  =  .875 

13-32  =  .40625 

13-64  =  .203125 

45-64  =  .703125 

15-32  =  .4^875 

15-64  =  .234375 

47-64  =  -734375 

i6ths. 

17-32  =  .53125 

17-64  =  .265625 

49-64=  .765625 

1-16  =  .0625 

19-32  =  .59375 

19-64  =  .296875 

51-64  =  .796875 

3-16  —  .1875 

21-32  =  .65625 

21-64=  .328125 

53-64  =  .828125 

5-16=  .3125 

23-32  =  .71825 

23-64  =  -359375 

55-64=  .859375 

7-16  =  .4375 

25-32  =  .79i?5 

25-64=  .390625 

5  7-64  ==.89062  5 

9-16  =  .5625 

27-32  =  .84375 

27-64=  .421875 

59-64=  .921875 

i  [  16  =  .6875 

29-32  =  .90625 

29-64  =  .453125 

61-64  =  .953125 

13-16  =  .8125 

31-32  =  .96875 

63-64  =  .984375 

15-16  =  .9375 

1  1 

i~  i 

UNIVERSITY 


INDEX 


Air —  PAGB. 

Mixtures  of  gases  in,  and  weight  of 71 

Measuring  heat  by  expansion  and  contraction  of 76 

Humidity  of,  in  cold  and  warm  weather 78,  306,  308 

Cubic  feet  required  to  melt  2,000  pounds  of  iron: 307 

Air  Furnaces — 

Advantages  of,  in  obtaining  strong  castings.254,  266,  273,  298 
Making  changes  in  the  character  of  iron  while  melting. . 

in     259,  343-344,  371 

Evils  of  an  oxidizing  flame  in 266,  290 

Class  of  iron  generally  melted  in 267,  273 

Chemical  changes  in  iron  by  remelting  in 290,  305 

Loss  of  iron  by  oxidation   in 290,  305 

Aluminum  — 

The  author's  first  experience  with 357 

As   alloyed    with   copper 358 

Manufacture  of  pure,  and  its  advantages 358 

How  used  and  its  effects  in  cast  iron,  etc 358-360 

Specific  gravity  and  melting  point  of 360 

Blast- 
Various  temperatures,  weight  and  composition  of 70 

Creation  of  carbonic  oxide  and  acid  gases  by 71 

Blast  Hot- 
Regulating   furnaces  by  varying  the  temperature  of.  .75,  77 
Appliances   used   for  measuring  degrees  of  heat  in....     76 
Advantages  and  operation  of  brick  stoves  for  making.  .79,  88 

Workings  of  iron  stoves  in  making 83 

Action  of  gases  in  creating 84 


596  INDEX. 

Blast  Furnace  Construction—  PAGE. 

Depth  of  foundations    34 

Form   and  position   of  hearth 35 

Different  lines  used  in 36 

Character  and  position  of  tuyeres 37 

Different  characters  of  coolers  used  and  their  position    38 

Amount  of  fire  brick  and  clay  required  to  line  up 40 

Character  of  bricks  used  and  time  required  to  line.  .41,  44 

Necessity  of  expansion  space  back  of  the  lining 41 

Methods  for  drying  and  life  of  linings 42,  43 

Factors  of  greatest  protection  to  lining 43 

Designs  of  bells  and  hoppers  and  their  use 49,  50 

Designs   of   appliances   and   methods   to   prevent   explo- 
sions     57,  85 

Advantages    of    increased    height 73 

Blast  Furnace  Operation— 

Weight  of  stock  charged  to  fill  a  furnace 36,  46 

Methods  for  keeping  tuyeres  open 37 

Length  of  time  furnaces  run  steadily.... 40 

Methods  of  charging 46,  47 

Actions  of  descending  stock 50,  51,  52 

Effects  of  improper  reduction  of  ores 53 

Factors  causing  scaffolding  and  slips 55,    58 

Relieving  gas  pressure  and  preventing  explosions 57 

Limits  of  fast  driving 76 

Conditions   causing   cold   and   hot   working 77 

Regulating  temperatures  of  blast 77 

Weight  of  water  driven  into  a  furnace  by  blast 78 

Methods   for   hand-tapping  and   stopping- up.  ..  .89,  90,  94-9^ 

The  weight  of  liquid  iron  in  bottom  of  furnace 91 

Causes  for  chilling  in  furnaces  and  evils  of  lime  sets. .     92 
Methods  for  burning  out  chilled  bodies  of  iron 93 

Blow  Holes  in  Castings- 
High  sulphur  in  iron  causing 21 1 

Manganese  assisting  to  prevent 213 

Oxides   and   occulated  gases  causing 213,409 

Phosphorus    assisting   to    prevent * 217 


INDEX.  597 

Blow  Holes  in  Castings— Continued.                                    PAGE. 
Pure  iron  causing 219 

Factors  causing  blow  holes  on  the  exterior  and  interior 
of  castings 296,  408,  409 

The  part  of  castings  blow  holes  are  found  in  and  their 
difference  from  shrink  holes .408,  409 

Brazing  Cast  Iron — 

A  method  for  and  details  of 585-586 

Carbon— 

Loss    of,    in    making    coke 9,19 

Amount  of  fixed  carbon  in  coke 19 

Desirability"  of  high  carbon  in  fuel 20 

Making  fire   bricks   of 44 

Variation  of,  in  pig  iron 131 

Uniformity  of,  in  like  grades  of  pig  iron 131,  153 

Diffusion  and  the  state  of,  in  pig  iron  and  castings.  .137,  138 

The  amount  iron  will  absorb 205 

Chromium's  great  affinity  for.  . '. 205 

The  state  of,  in  grey  and  white  irons 206,  268,  269 

State    of,    in    molten    iron 206,  420 

Rate    of    cooling    affecting    the    state    of,    combined    or 

graphitic     206,  221,  264,  268,  420,  422 

Determining  the  amount  of,  in  pig  iron  or  castings....  207 

Effects  of  variations  of  total  carbon  on  iron 246 

Dirty  castings  caused  by  high 246 

Low  silicon  iron  containing  the  highest 247,  280 

Impracticability  of  regulating  mixtures  by  carbon 247 

Its  influence  to  increase  heat  in  molten  iron 247 

Percentages  best  to  insure  fluid  metal  and  clean  castings  248 

Silicon  required  according  to  variation  in 248,  280,  282 

Division  of  carbon  into  hardening,  carbide  and'  tem- 
per-carbon   261,  266,  267 

The  difference  in  the  state  of  carbon  in  gray  and  chilled 

parts  of  car  wheels 268,  269 

Mixing  steel  with  iron  to  lower  the 290 

Increase   and   decrease   by   remelting   iron 304 

Increase  of  carbon  about  i%  by  five  remelts 34© 


598  INDEX. 

Carbon  Combined—  PAGE. 

Variations  in  the  sand,  ramming  and  venting  affecting 

the 137,  138,  454,  485 

Its  appearance  in  fractures  206 

Where   the   lowest   is    found 206 

Variations  of,  being  more  effective  than  graphite  in  alter- 
ing the  grade  of  iron 207 

The  importance  of  understanding  the  effects  other  ele- 
ments have  in  forming 262 

Determining  its  utility  in  electrical  work  castings 284 

Power  of  sulphur  and  manganese  to  promote 285,  420 

The  thickness  of  a  casting  and  the  time  taken  to  solidify 

and    cool    regulating   the 286,  420,  422,  453 

Tests  proving  that  the  higher  the  combined  carbon,  the 
lower  the  melting  point  of  metals 354,  355 

Carbon,  Graphitic — 

Removal  from  fracture  and  grain  of  iron  by  brushing.  ...   117 

Methods  of  moulding,  altering  percentage  of 137 

Rate      of      cooling      castings      affecting      the      creation 

of    167,  221,  286,  420-422 

Its  effects  in  decreasing  the  contraction  of  iron 395 

Its    appearance    in    fractures 206 

Enlarging   the   grain   of   iron 420-421 

Principles  involved  in  the  formation  of 420,  421 

Carbonic  Oxide  and  Acid  Gases- 
Heat  units  contained  in  and  creation  of 71 

Explosive  nature  of  oxide  gas 86 

Castings — Gray  and  General — 

Best  composition  to  resist  fusion  or  high  temperatures. .  230 

Different   kinds   made,    showing   forty    specialties 252 

Character  of  those  having  steel  scrap  mixed  in.  .265,  267,  275 
Description  of  the  color,  grain,  etc.,  of  different  grades 

of  iron   used  in 461-469,  558-569 

The  A.  F.  A.  specification  for  test  bars  and  gray  iron. 580- 583 


INDEX.  599 

Castings,  Chilled—  PAGE. 

The  different  kinds  used 254,  263 

Lines    of   crystallization    in 259,  434 

Necessity  of  tests  in  making 259 

Difference  between  the  wear  of  heat  and  friction  upon.259,  264 

Difference  in  the  hardness  of 259,  260,  444 

Peculiar  effect  of  sulphur  and  manganese  upon  the  hard- 
ness of 259,  260,  271 

Factors  affecting  and  preventing  "cola  shuts"  and  "chill 

cracks"    in 260,  262,  415 

Interlacing  of  the  gray  body  with  a  chill  of .261,  264 

General  composition  of 262 

Temperature  of  molten  metal  partly  regulating  the  depth 

of  chill   in    262,  373,  433 

Mixtures  for  rolls,  and  points  to  be  considered  in  mak- 
ing     263,  266 

Thickness  of  chill  used  in  rolls 263 

Sharply  defined  chill  in  joining  gray  body  of 264 

Difference  required  in  the  chill  of  rolls  used  for  cold  and 

hot  rolling  264 

Analyses  of  roll  mixtures 205,  266,  267,  299,  570 

Analyses  of  car  wheels  showing  difference  between  the 

chilled  and  gray  parts 268,  269,  270 

Thicknesses  of  chill  used  in  car  wheels 271,  446 

Annealing  car   wheels 448 

Castings,  Malleable- 
Principles    of    annealing 288,  289,  290 

The    depth    decarbonizing    affects 289 

Contraction   and   expansion   of,   and   percentage   of   sili- 
con  in 289 

Castings,  White  Iron- 
Factors   to   be    considered   in   making 287 

Difference  in  the  strength  of 287 

Percentage    of    silicon   to    make    castings    ranging    from 

one-half  inch  to  four  inches  thick 288 

Necessity  of  larger  gates  to  pour  white  than  gray  iron 

and  the  difference  in  their  shrinkage  and  contraction.  .  288 
Practicability  and  process  of  annealing 288 


6OO  INDEX. 

Chemical  Analyses,  the  Utility  of—  PAGE. 

Conditions  exacting  complete  analyses   of  irons. ..  .132,  197 

Methods  of  sampling  pig  iron  to  make 140,  195,  196 

Opposition  to  mixing  and  grading  by 163 

Self-interest    retarding    past    advancement    and    adop- 
tion of    164,  166 

Difficulty  of  securing  uniform 180,   181,  182 

The   evils   resulting   from   non-uniformity   of 180,  182 

Variation  found  in  analyses  of  one  sample  of  drillings 

by  two  investigators  to  test  the  utility  of 180,  181 

Difficulty  of  chemists  knowing  the  correctness  of.  ..  .181,  182 

Number  of  founders   using 194 

The  wisdom  of  founders  checking  blast  furnace  analyses 

and    the    chances    for    mistakes    in 194,  195 

The  simplicity  of  founders  mastering  the  knowledge  of 

working    by 195,  198 

Difficulty  of  small   founder  utilizing  analyses,  and  how 

to   best   overcome    it 196,  197 

The    necessity    of    utilizing 205,262 

Benefit  to  founders  in  making  chilled  castings 258 

The  necessity  of  working  by,  in  making  chilled  castings  262 
Same  analyses  in  different  irons,  not  giving  like  hard- 
ness to   like  castings 282 

Chill  Tests— 

The  character  of,  and  how  made.  .220,  432,  502,  506,  513,  551 
Effect  of  different  temperatures  in  varying  the  depth 

of '  . . . . • 262,  373,  433 

As  a  guide  to  the  tensile  strength  of  semi-steel 277 

Chill  test  moulds  adapted  to  blast  furnace  and  foundry 

work  , 502-508 

Chill  tests  for  round  bars  cast  on  end 513,  515 

Chill  and  fluidity  strips  used  for  the  A.  F.  A.  series  of 

tests 548,  551,  56i 

Chrome-  Ferro— 

Refractory  nature  and  behavior  in  a  molten  state 218 

Clays- 

Quality  required  and  use  of  in  lining  furnaces 41 

Grades  used  for  manufacturing  fire  bricks. 44 

Kind  used  for  stopping  up  furnaces 98 


INDEX.  601 

Coke—  PAGE 

By-products   ovens   for  making 3,  6 

First  successful  use  of 3 

Advantages  of  coal  over 3 

Principles  involved  in  making 4 

Natural,    where    found 6 

Operation  of  oven  for  making 6-13 

Braise  in  . . .- ' 9 

Moisture  in   g,  n,  307 

Removal  of  pyrites  and  slate  from n 

The  yield  obtained  from  ovens 13 

Density  and  cell  structure  of 13,  14 

Physical  tests  and  chemical  analyses  of 15,  18 

Difference  in  forty-eight  and   seventy-two  hour 16 

Twenty- four,   ninety-six,   and    124-hour   coke 17 

Gas  house  coke  and  its  utility 17 

Sulphur  and  phosphorus  in 18,  21,  22 

Different  makes  of 18 

Black  ends  and  black  butts  in 18 

Qualities  in  good  and  poor 18 

Localities  conceded  to  produce  the  best 18,    23 

Stock  coke,  how  created  and  its  utility 19 

Percentage  of  fixed  carbon  in 19 

Ash,  its  composition  and  percentages  in 20 

Chemical  properties  desirable  in 20 

Evils  of  scarcity  of  good  water  in  making 22 

A  quick  test  for  sulphur  in 22 

Weight  of  soft  and  hard  coke  per  bushel 23 

Different  amounts  of  hard  and  soft  coke  required  to  melt  23 
Conditions  under  which  greatest  heat  is  obtained  from. .  75 
Amount  of  coke  theoretically  required  to  melt  iron 307 

Compression  Tests  of  Iron — 

The  transverse,  deflection  and  chill  of  an  iron  a  good 
index  to  439 

As  obtained  in  different  grades  of  iron  by  the  A. 
F.  A 558,  560,  562 


602  INDEX. 

Contraction  of  Iron —  PAGE. 

Sulphur  causing  excessive  shrinkage  and 212 

Diagram  showing  the  effect  of  expansion  and  after  con- 
traction of  different  grades 389-390 

Confined  expansion  giving  rise  to  greater  contraction.  ..  .  389 
Light  bodies  contracting  more  than  heavy,  causing  in- 
ternal   strains    in    castings    390,419,421,440 

The  relation  that  shrinkage  maintains  to 414 

Difference  in   contraction  between  light  bars,  cast  in  a 

sand  and  a  chill  mould 414 

Comments  on  contraction,  showing  why  founders  mak- 
ing chilled  castings  have   difficulty  with 415 

Impracticability  of  set  or  standard  rules  for 418,  422 

Cases  where  castings  are  larger  than  their  pattern 419 

Difference  in  the  contraction  of  light  and  heavy  castings  420 

Principles  involved  in  creating 420,  421 

Evils  of  internal  contraction  strains 440 

Amount  allowed  in  car  wheels  for 444 

Designing  car  wheels  to  best  withstand 446 

Variations  in  the  dampness  of  sand  and  pouring  tempera- 
tures affecting  the  strength  and  contraction  of  small 

and   large   bodies 454-457,  484,  511 

Excessive  contraction  causing  castings  to  crack  and  fly  to 
pieces    466 

Crucibles- 
Objections  to  use  of  for  melting  iron 363,  459 

As  used  in  melting  iron 365 

Care  necessary  in  preserving 367 

Cupola  Construction  and  practice — 

Plans  for  stopping  up : 98 

Methods    for    banking 126-129 

Plans  for  conveying  iron  to  and  mixing  ready  for  charg- 
ing in  198 

One    system    for    recording    the    chemical    and    physical 

properties   of  mixtures   melted   in 199 

Plans  for  constructing  small 241,  364,  501 

As  used  for  testing  different  pig  irons 259,  262,  267 


INDEX.  603 

Cupola  Construction  and  Practice—  Continued^  PAGE. 

As  used  for  making  strong  castings 277-279 

Reasons  for  different  strengths  of  iron  being  obtained 

from  the  same  mixture  in  same  heat 306 

As  prepared  for  testing  oxidation  of  iron 310 

Loss  of  iron  by  oxidation 310,  318 

As  arranged  for  testing  the  comparative  fusibility  of 

metals  . 325 

Methods  for  preparing  and  charging  small. 

325-327,  364,  499,  500 

Combination  small  crucible  furnace  and  cupola 364 

Utility  of  small  for  blast  furnaces 495 

Cost  of  a  small  cupola  for  testing  purposes 496 

Pressure  of  blast  in  small 499 

Direct  Hetal— 

Evils    of   kish    in 117-118 

Its  utility,  and  methods  for  handling 117,  119 

The  life  and  fluidity  of 118 

Best   grades   to   use i  i8f  120 

Character  of  castings  best  made  of 118,  120 

Drop  Test  for  Castings— 

As  used  for  testing  car  wheels , 446-448 

Etching  Steel  and  Cast  Iron- 
Details  for  and  prints  of 587,  588 

Expansion  of  Iron — 

Annealing  white  and  malleable  causing 289 

At  moment  of  solidification,  demonstration  of..  .386,  387,  427 
Causing  shrinkage  and  the  necessity  of  feeding  to  make 

solid  castings   387,  392 

Hard  grades  expanding  more  than  soft 387,  389,  394 

Diagrams  displaying  expansion  and  contractions  of  dif- 
ferent irons  389,  390 

Retarding  expansion  giving  rise  to  greater  contraction.  .  389 
Expansion  unaffected  by  temperature  of  molten  metal..  391 
Period  of  expansion  varying  with  the  size  of  casting 392 


604  INDEX. 

Expansion  of  Iron — Continued.  PAGE. 

Confined  expansion  decreasing  shrinkage  and  contrac- 
tion    394 

Views  of  appliances  used  to  test  expansion  and  contrac- 
tion   398-402,  424 

The  practicability  of  utilizing  expansion  tests  of  iron  to 
define  its  grade 427 

Fire  Bricks- 
Composition  of  and  different  kinds  used 44 

Composition  which  stands  heat  and  friction  best 44 

Fluxes  and  Their  Use — 

Amount  required  in -fluxing  furnaces. 46,  53 

The  object  of  fluxing 59 

Elements  essential  in  and  the  different  kinds  used 59 

Effects  of  silica  in 60 

Physical  character  of  some  grades  of 6l 

Object  of  roasting 62 

Chemical  character  of 63 

Variation  in  the  grain  of  pig  iron  by  variation  in  use  of. .  64 

Formulas — 

Best    adapted    for    computing    comparative    strength    of 

standard  test  bars 474-477 

Lack  and  need  of  perfect  formulas 476,  477,  530 

Fuels- 
Charcoal  as  used  in  making  iron 161 

Charcoal,  its  freedom   from  sulphur 162 

Fusibility  of  Iron,  Comparative  Tests  of— 

Effects  of  adding  phosphorus  to  molten  iron  as  defined 
by  immersion  test 230,  232 

Comparative  fusing  tests  of  small  sand  and  chilled  roll 
castings 312,  332,  335 

Immersion  tests  of  small  sand  and  chill  rolls 314,  415 

Importance  of  knowing  comparative  fusibility  of  differ- 
ent irons  323 

Conditions  necessary  to  test  the 324 


INDEX.  605 

Fusibility  of  Iron,  Etc.— Continued.  PAGE. 

Comparative  fusing  tests  of  hard  and  soft  irons  in  a 
cupola  328-330 

Comparative  fusing  tests  of  hard  and  soft  iron  in  an 
open-hearth  furnace  331-332 

Comparative  fusing  tests  proving  that  the  chilled  remelt 
is  softer  than  the  grey  of  the  same  chilled  casting.  .337-339 

Comparative  fusing  tests  of  cast  iron  and  steel 342-344 

Comparative  fusing  tests  and  melting  points  of  iron, 
chromium,  tungsten  and  manganese  (72  sampks)  in  an 
essaying  furnace  35O-353 

Comments  on  fusibility  and  melting  points  of  metals.  ..  .  355 

Hardness  Tests- 
Impracticability  of,  for  testing  the  grade  of  pig  iron.  .175,  176 

Methods  used  for  testing  hardness 234-238,  434-438 

Past   unsatisfactory   nature   of 434 

Heat- 
Units  of,  in  carbonic  oxide  and  acid  gases 71 

Production,  absorption  and  loss  of,  in  furnaces 72 

Appliances  for  measuring 76 

Influence  of  carbon  in  iron,  to  increase 247 

Radiation  of,  in  test  bars 484,  485,  487 

Illustrations- 
Plan  of  Bee,  hive  coke  ovens 8 

Coking  in  mounds 10 

Drawing  coke  from  ovens 12 

Loading  coke  for  shipment 21 

Buchanan  separator  for  dephosphorizing  ores 28 

Elevation  view  of  blast  furnace 35 

Views  of  modern  blast  furnace 46,  47,  48 

Action  of  stock  descending  a  furnace 49 

Operation  of  furnace  bell  and  hopper 50 

Mr.  P.  C.  Reed's  gas  escaping  device 57 

Massick  &  Crooke's  brick  hot  blast  stove 80 

Iron  hot  blast  stoves 81,  83.  84 


*This  work  contains  153  illustrations. 


6o6  INDEX. 

Illustrations— Continued.  PACTS. 

Illustrations  of  tapping  and  stopping  furnaces 90 

Burning  out  chilled  furnaces 93 

Stopping  tools  94 

Tapping  and   stopping  up  cupolas 98 

Molding,  casting  pig  iron  and  open  sand  work..ioi,  103,  104 

Views  of  sand  and  chilled  cast  pig  iron 116 

Samples      showing      deceptive      appearance      of      pig 

fracture 167,  168,  170,  173 

Hardness  tests  of  pig  iron 177 

Method  of  moulding  and  pouring  a  standardized  drill- 
ing casting  185 

View  of  sample  case  of  standardized  drillings 189 

Methods  for  sampling  pig  iron 195 

Appliances  for  handling  phosphorus 229 

Testing  the  fusibility  of  metals  by  immersion..  .232,  416,  417 

Device  for  testing  contraction  of  test  bars 237 

Drill  press  arranged  to  test  hardness  of  metals 239 

Methods  for  measuring  hardness 239,  240 

Twin  shaft  cupola  241 

Section  of  chilled  cast  car  wheel 264 

Chill  mould  and  casting  of  small  roll 312 

View  of  the  fracture  in  a  gray  and  chilled  roll.  .333,  337,  338 
Chatelier   Pyrometer   arranged  to  measure   the   melting 

point    of   iron,    etc 346,  347,  348,  354 

Combined  cupola  and  crucible  furnace 364 

Fracture  of  chills  poured  with  hot  and  dull  iron 373 

Plan  for  casting  fluidity  strips  flat 375 

Device  for  measuring  expansion  of  J^-inch  sq.  bars 384 

Diagrams  of  automatic  expansion  records 389,  390 

Apparatus   for  recording  expansion  and  contraction  of 

metals    398,  400,  401,  402 

Typical  position  of  shrink  holes 405,  406,  407 

Castings  showing  internal  and  external  blow  holes 408 

Shrinkage  test  pattern  and  casting 409 

View  of  pouring  shrinkage  tests 410 

Contraction  chill  and  sand  test  mould 413 

Apparatus  for  recording  stretching  qualities  of  iron....  424 


INDEX.  607 

Illustrations— Continued. 

Sketch  of  patterns  for  testing  stretching 425 

Prof.  Turner's  machine  for  testing  hardness 436 

Method  for  thermal  test  of  car  wheels 444 

Drop  testing  machines  for  car  wheels 447 

Thirty  views  of  the  fracture  of  test  specimens 472,  473 

Beam  of  testing'  machine  and  testing  bars  transversely.  .  482 

Views  of  radiation  of  heat  in  round  and  square  bars 484 

Difference  of  uniformity  in  grain  of  round  and  square 

bars 486 

Difference  in  grain  of  the  cope  and  nowel  side  of  flat 

poured  bars 409-491 

Small  cupola  for  testing  purposes,  etc 501 

Flask   and   pattern    for   ramming  flat   test   bars   cast   on 

end  503,  507,  509 

View  of  chill  moulds  for  making  chilled  tests 506 

Patterns  and  flasks   for  round  bars  with  fluidity  strips 

moulded  flat  and  cast  on  end.  .514,  515,  516,  522,  524,  527 
Moulding  and  casting  plain  round  bars  on  end.... 527,  578 
A  set  of  198  test  bars  of  Bessemer  iron  for  A.  F.  A. ...  541 
Patterns  and  boxes  for  the  A.  F.  A.  tests. 543,  544,  546,  548 
Malleable  flasks  for  moulding  A.  F.  A.  green  sand  bars.  .  549 
Moulds  in  place  for  casting  a  set  of  A.  F.  A.  bars....  550 
Plan  and  elevation  sketch  of  A.  F.  A.  test  bar  moulds. .  552 

Plan  of  runners,  pouring  A.  F.  A.  bars 554 

View  of  casting  a  set  of  A.  F.  A.  bars 556 

Device    for    imprinting   contraction    tips 557 

Fracture    views    of   chilled    test    pieces    obtained    by    A. 

F.  A 559,  561,  563 

Transverse  and  tensile  test  bars  recommended  as  stand- 
ards by  A.  F.  A 582,  583 

Impact  or  Shock  Tests  of  Iron- 
Instances  of  their  impracticability 439 

A  practical  way  to  apply 440 

As  conducted  in  tumbling  castings  proving  beneficial. . .  .  441 
Desirability  of  gradually  increasing  the  severity  of  shock 
tests  in  castings  required  to  stand  sudden  shocks,  etc.  .  442 


608  INDEX. 

Iron—  PAGE. 

Refining  and  the  character  of  pure 162,  218 

The  metallic  and  non-metallic  elements  of 202 

Composition  of  atoms  and  molecules  and  number  of  ele- 
ments  in    202-203 

The  general  acceptance  of  the  terms  metal  and  metalloid 

to  define   elements   in 202-203 

,          Method  of  distinguishing  metallic  from  non-metallic  ele- 
ments in    203 

Constituents  of  218 

Definition  of  tenacity,  elasticity,  toughness,  strength,  brit- 

tleness  and  chill  of 220 

The  evils  of  excessive  impurities  in  249,  250 

Elements  that  constitute  impurities  in 249 

Character  of  iron  which  shows  the  least  impurities....  250 

The  brand  of,  most  free  of  impurities 250 

A  method  of  determining  the  metallic  iron  in 251 

Iron  Mixtures  and  Analyses — 

Utilizing   Bessemer   iron   in   making  ingot   moulds   and 

other  castings  157,  253,  537,  55$ 

Using  ferro-silicon  in  emergency  cases  to  make 211 

For  stove  plate  and  light  machinery  castings 

253,  281-283,  299,  465,  537,  562,  566,  568 

For  medium  weight  gray  iron  castings.  ..  .253,  280,  299,  464 
For  heavy  gray  iron  castings 

253,  273-280,  299,  463,  537,  564,  570 

Of  stove  plate,  burnt  grate  bars,  annealing  pots  and  tin 

sheet  scrap  253,  296,  299,  466,  565 

For  cannonsvguns,  etc. 253,  274,  275,  278,  279,  299,  460,  537  560 

For  car  wheels  253,  267-271,  299,  462,  537,  566,  570 

For  chilled  rolls. 254,  265,  266,  267,  299,  461,  536,  537,  564,  570 

Methods  for  calculating  the  analyses  of 255-257 

Greater  difficulty  of  making  mixtures  for  chill  than  gray 

castings  258 

Factors  to  be  considered  in  making  chilled  rolls 

259-261,263  -265 

General  composition  for  chilled  castings 262 

Character  of  pig  iron  and  scrap  used  for  chilled  rolls. . . .  265 


INDEX.  609 

Iron  flixtures  and  Analyses — Continued.  PAGE. 
Si.ee!  employed  in  and  how  used 

265,  271,  273,  276,  342-344,  568 

Analyses  of  chilled  rolls 265,  266,  267,  299 

Difference  in  mixtures  for  chilled  rolls  and  car  wheels. .  267 

Analyses  of  car  wheels  268,  269,  270,  299 

Analyses  of  the  gray  and  chilled  bodies  of  car  wheels 

268,  269 

For  sand  rolls 273,  564,  570 

Analyses  of  some  specially  strong  gray 

274,  275,  276,  278,  299 

Approximate  analyses  of  coke  iron  mixtures  for  castings 

ranging  from  ^2"  to  4"  thick 280 

For  dynamo  castings  and  those  used  to  transmit  electric 

currents  284 

Analyses  of  gun  iron,  chill  rolls,  car  wheels,  light  and 

heavy  machinery,  stove  plate  and  white  iron,   etc.... 

299,  537,  570 

Three  methods  for  melting  small  samples  to  test 362 

Non-scientific  practice  of  mixing  irons  prior  to  1890....  497 

Iron  Ores- 
Oxides  and  impurities  in.... 25 

Definition  of  lean  and  rich 25 

Percentages  of  iron  and  silica  contained  in  commercial 

ores     26 

The  function  of  silica  in 26 

Percentage  of  manganese  in 27 

High  and  low  phosphorus  in 27 

Methods    for   dephosphorizing   magnetic 28 

Classification  of  hematites,  magnetites  and  carbonates. .  29 
Characteristics  of  brown  hematites,  carbonates  and  spathic  30 
Titaniferous  ores  and  manufacture  of  ferro-titanium.3i,  218 

Mill  cinder  in  mixture  with 32 

Effects  of  varying  temperatures  in  reducing 52-53,  71 

De-oxidation  of  52,  72 

Reduction  of  non-metallic  matter  in 52 

Scaffolding   furnaces   by   expansion  of 56,77 

Different  composition  of,  from  same  mine 131 


6 10  INDEX. 

Kish —  PAGE. 

Its  production  and  appearance  at  blast  furnaces. ..  .117,  369 

Evils  of  in  metal 117-118,  248 

Difficulty  of  eliminating  from  metal 1 18 

Grades  of  iron  most  free  of 120,  248 

Created  in  remelted  iron  by  high  carbon 248 

Limestone- 
Affinity  for  sulphur 53,    60 

Chemical  and  physical  character  of 61 

Roasting  of   62 

flanganese— 

Percentages  in  ore  and  manufacture  of  ferro- 27 

Uniformity  of,  in  like  grades  of  iron 136,  151,  153 

Percentages  in   different  brands  of  pig  iron.  ..  .145-147,  213 

Influence  of,  in  causing  iron  to  absorb  carbon 205 

Its  influence  to  harden  iron  without  closing  grain     or 

changing  soft  appearance  in  fractures 206,  213,  286 

Its  peculiar  effect  on  hardness  and  chill  compared  with 

that  of  sulphur 211,  260,  271 

Its  general  tendency  to  strengthen  iron 212,  244,  245 

Percentages  in  pig  iron  and  amounts  permissible  in  cast- 
ings      213,  282 

Its  power  to  neutralize  the  effects  of  sulphur 213,  260 

Increasing  the  life  and  fluidity  of  molten  metal 213,  262 

Beneficial  as  a  flux  to  expel  oxides  or  occulated  gases  in 

metal   213,  297 

Loss  of,  by  remelting  iron. . .  .214,  257,  271,  295,  300,  315,  341 

Methods  for  adding  it  to  molten  metal 214,  241 

Its  power  to  soften  a  low  grade  of  iron  when  added  to 

molten    metal    214,  243,  244 

Results  of  experiments  in  adding  manganese  to  molten 

iron     241,  243 

Its  peculiar  effects  in  driving  graphite  to  the  surface  of 

castings    244 

Evils  of  mixing  with  dull  iron 244 

Strengthening  white  iron  by  the  addition  of 245 

Essential  in  car  wheels  to  assist  them  in  standing  ther- 
mal tests  271 

Percentage   admissible    in    light    castings 282 


INDEX.  6ll 

letting  Iron —  PAGE. 

In    small    cupolas    to    make    experiments    or    test    mix- 
tures      238,  325,  364,  495,  499-502 

In  a  crucible,  and  how  to  operate  it 363,  367 

Holten  Iron- 
Composition  of  a  flux  to  purify. . .  276 

Exposition  of  some  fluxes  used  in 277 

Judging  the  grade  of  iron,  when  solid,  by  the  appear- 
ance of    369 

Actions  and  appearance  of  different  grades  in 369-371 

The  utility  of  thin  tapering  strips  on  test  bars  to  test  the 

fluidity  of 502,  515-517 

Best  temperature  for  pouring  test  bars 526 

Oxidation  of  Iron.    Loss  by  netting,  Etc.— 

Methods  of  preparing  cupolas  to  test 310 

Difference  of  sand  coated  and  chilled  iron 311,  318 

Comparative  tests  of  iron  on  low  and  high  beds  of  fuel. . 

3U,  315 

Comparative  tests  of  stove  plate  and  heavy  iron. 314,  317,  318 
Summary  notes  on 322 

Phosphorus— 

The  utility  of  fuels  containing  low  and  high 22 

Advantage  of  low  phosphorus  in  ores  for  certain  irons. .  27 

Methods  of  dephosphorizing  ores 28 

The  most  effective  element  in  increasing  life  and  fluidity 

of  molten  metal 28,  216,  226,  282,  285 

As  found  in  mill  cinder 32 

Uniformity  in  like  grades  of  iron 136,  151,  153 

Percentages  in  different  brands  of  pig  iron 145-147 

Percentages  beneficial  to  toughness  in  castings.  .158,  216,  274 

As  found  in  Bessemer  and  Foundry  irons 215 

High  phosphorus  causing  brittle  and  hard  castings.... 

216,  282,  285 

How  it  is  obtained  in  iron 216 

Its  effect  in  neutralizing  the  evils  of  sulphur 217 

Effects  of  adding  to  molten  iron 226 

Strengthening  castings  by  adding  it  to  molten  metal....  227 


6l2  INDEX. 

Phosphorus—  Continued.  PAGE. 

Its  influence  to  flux  and  drive  off  impurities 227 

Methods  for  adding  phosphorus  to  molten  metal.  ..  .228-230 
Percentages  best  adapted  to  increase  fusibility  of  iron..  230 
Testing  the  fusibility  of  phosphorus  iron  mixtures.  .231-232 

Increased  by  remelting  iron 257,  304,  341 

Effects  of,  upon  chilled  iron 261 

Percentage  used  in  light  castings 282 

Pig  Iron- 
Percentages  of  impurities  in 26 

Manufacture  of  mill  cinder  mixed 31-33 

Carbonizing  in  furnace 52 

High  sulphur  and  silicon  in  the  same  grade  of 54 

Methods  for  moulding  and  pouring 99-111 

Causes  for  boils  in  making 100,  105 

Character  of  sand  required  in  making 100,  105 

Cause  of  jump  cores  in  making 102 

Breaking  and  removing  pig  iron  from  casting  house 106 

Designs  for  patterns  for  moulding no 

Principles  involved  in  casting  chilled  or  sandless 113 

Parties  manufacturing  machines  for  casting  chilled 113 

The  economy  and  advantages  obtained  by  using  chilled. .   114 

Recommendations   for  chilled 115 

Difference  in  the  form  of  sand  and  chilled 116 

Difficulty  in  controlling  silicon  and  sulphur  percentages 

in  making   130,  137 

Changeable  and  constant  metalloids  in  making 132 

The  grade  giving  the  least  difficulty  in  making 132 

Segregation  of  metalloids  in  making 134-13? 

Analysis  of  gray  spots  in 134 

Desirability  of  using  hot  melted 137 

Evils  of  dull  melted 138 

Mixing  effects  obtained  by   remelting 138 

Necessity  of  mixing  blast  furnace  casts  of I 39-143 

Plans  of  mixing  at  furnace  and  foundry  for  charging.  140-142 

Method  of  sampling  to  make  analyses  of 140,  195-196 

Advantage  of  casting  chilled  pig  from  ladles 142 

Objectionable    methods    of    analyzing 142,  143 


INDEX.  613 

Pig  Iron— Continued.  PAGE- 

Evils  of  using  ill-mixed  casts  of 139-143 

Best    method    of    grading M4-I45 

Definition  of  "brand"  and  "grade"  of 144,  396 

Difference  between  Foundry,  Charcoal,  Bessemer,  Gray 
Forge,  Basic,  Ferro-Silicon,  Ferro-Manganese,  Mottled 

and  White    145-147 

Number  of  founders  in  1901  grading  by  analyses 148 

Deceptive  appearance  of  the  fracture  of.  .148,169,173,177,  178 
Suggested  systems  for  standardizing  grading  by  analy- 
ses     148-153 

Erratic  and  objectionable  systems  of  grading  by  analy- 
ses practiced  up  to  1902 149 

Percentage  of  silicon  required  to  change  the  grade  of.  150,  155 
Desirability  of  occasional  analyses  of  all  metalloids  when 

purchasing   Ferro-Silicon    152,    154,  197 

Conditions  requiring  analyses  of  all  five  metalloids 153 

Suggestions  to  furnacemen  for  advertising 154 

Impracticability     of     exacting     certain     percentages     of 

graphite  or  combined  carbon  in  purchasing 154 

Methods  for  utilizing  different  grades  to  make  a  mix- 
ture       155 

The  value  of  standardized  drillings  in  analyzing 

156,  181,  192 

Process  of  refining  162 

Excuses  to  account  for  ill  results  through  being  guided 

by  the  fracture  of 164.  165,  170 

Tests   demonstrating  the   deceptive  appearance  of  frac- 
tures  in    : 172,  174 

Impracticability  of  hardness  tests  for  judging  the  grade 

of    175-176 

Two  ways  of  producing  hardness  in 175 

The  percentage  of  furnace  casts  that  will  be  deceptive 

in   fractures  of    , 176-179 

Necessity   of   utilizing   analyses   and   physical   tests   and 

what  they  define  in  making  mixtures  of.  .194,  205,  258,  497 
Evil   practice   of   foundrymen   relying   upon   furnacemen 
to  tell  them  what  they  should  use 197 


6 14  INDEX. 

Pig  Iron — Continued.  ,  PAGE. 

A  good  plan  for  beginners  to  follow  in  first  purchas- 
ing   200,  283 

The  fallacy  of  considering  the  grain  of  pig  metal  in  con- 
nection with  chemical  analyses 200 

The  gross  weight  of  sand  and  chilled  cast   309,  589,  590 

The  fallacy  of  claiming  bad  iron  for  ill  results 497 

Pig  Iron,  Bessemer- 
Utility  of,  for  certain  kinds  of  castings  and  mixtures 

of 146,  157 

The  restrictions  which  define 146,  159,  215 

Impracticability   of    defining    it    from    Foundry    iron    by 

fracture    157,  160 

Pig  Iron,  Charcoal — 

Highest  silicon  in 146,  245 

Being  replaced  by  coke  and  anthracite  iron 160,  267,  279 

Pronounced  character  of  its  fracture.  How  defined  from 

other  irons 160-261 

The  element  causing  strength  in  castings  made  of 161 

Deterioration  of  by  melting  in  cupolas 162 

Peculiarity  and  its  advantage  over  coke  and  anthracite 

pig  iron  often  due  to  low  sulphur 211,  212,  261 

The  softest  strong  casting  made  of 212 

Difference  in  and  advantage  of  cold  and  hot  blast.  .265,  274 
Some  special  brands  of  strong 274,  275,  278,  279 

Pig  Iron,  Gray  Forge  and  Basic- 
Limitation  of  elements  in 146 

Utility  of  and  appearance  of  fracture. . .' 146 

Pig  Iron,  Hottled  and  White- 
Conditions  of  furnace  making,  and  analyses  of 147 

White  iron  strengthened  by  the  addition  of  manganese. .  245 
Annealing  white  iron  castings 288 

Pig  Iron,  Ferro-Manganese— 

Spiegeleisen  or  Spiegel,  its  power  to  absorb  carbon.  ..27,  205 

Analyses  of  and  standards  for 27,  241 

Utility   of    27,  214,  241,  297 


INDEX.  615 


Pig  Iron,  Ferro-SHicon— 

Kind  of  fuel  and  ores  used  to  make  .................  26,  147 

Erratic    composition    of  ................................   15^ 

Utility  of   ....................................  210,  211,  293 

Using   ferro-silicon   in   emergency  cases  to   make   mix- 

tures    ..............................................    211 

Pyrometers- 

Designs   of    .  .....................  .  .................  76,  344 

Methods  for  using  ..............................  76,  345-349 

Sands- 

Adaptability  of  coarse  grades  for  moulding  pig  iron.ioo,  112 
Variations  in  the  "temper"  of,  affecting  the  carbons,  con- 
traction and  strength  of  iron  ............  451,  453-457,  484 

The  "temper"  of  sands  best  for  moulding  test  bars..  523,  580 

Scrap,  Iron  — 

Castings    requiring    only  .......................  253,  272,  296 

Methods  of  grading  chilled  ........................  265,  294 

Percentage  of  shop  scrap  made  in  light  and  heavy  work 

foundries     ..........................................  281 

Difficulty    of    analyzing    miscellaneous  .................  292 

Imaginary  basis  to  define  chemical  properties  of  ........  292 

The  evils  of  using  burnt  ............................  295-297 

Approximation  of  analyses  in  and  rules  for  grading.  .  .  .  295 

Injurious  effects  of  rusty  and  methods  for  fluxing  ......  296 

Chilled  bodies  of  the  same  casting  giving  a  softer  re- 

melt  than  gray   ..................................  337-339 

Scrap,  Steel  and  Wrought— 

Using  steel  in  iron  mixtures  ..........  265,  271,  275,  276,  344 

Using  wrought  in  iron  mixtures  ....................  271-272 

Comparative    fusibility    of    ........................  342,  355 

Increase  of  carbon  in  by  remelting  .................  343,  355 

Semi-Steel— 

First   introduction   of  ..................................  276 

Refutation  of  some  claims  made  for  high  strength.  ..277,  343 


6l6  INDEX. 

Shrinkage  vs.  Contraction—  PAGE. 

Difference  in  their  action 386 

Elements  affecting  their  application  in  foundry 

394-395,  4H-4I5 

Shrinkage  of  Iron — 

Principles  involved  in  causing 387,  392 

The  constant  relation  existing  between  expansion  and...  387 
Not  increased  by  hot  poured  metal,  as  generally  thought  391 
The  factors  causing  hard  iron  to  possess  greater  shrink- 
age than  soft  iron 391,  394,  395 

That  period  of  solidification  which  exacts  the  greatest 

attention  and  feeding  to  supply  the 393 

Metal  poured  into  iron  moulds  showing  less  shrinkage 

than  into  sand 394 

The  part  in  which  shrinkage  will  occur,  if  any  exists. 404,  485 
The  necessity  for  engineers,  designers  and  draftsmen  to 

understand  the  principles  of 404 

Illustration  of  castings  showing  typical  position  of  shrink 

holes  " 405,  406,  407 

Tests  to  ascertain  the  percentage  of  shrinkage  occurring 

in  hard  and  soft  grades  of  iron 409-413 

The  amount  gray  and  chilled  iron  shrinks  per  100 

pounds    411-413 

Silica- 
Effects  of  temperatures  on,  and  its  refractory  nature. 26,    60 
Percentage   in   ores   and   fuel   and   amount   absorbed   in 

making  iron  26 

Amount  taken  up  by  iron  and  carried  off  in  slag 26,  66 

Silicon- 
How  obtained  in  iron 26,  53-54 

Temperatures    in    furnace    regulating   percentage    of,    in 

iron    26,  53-54 

Diffusion  of,  in  pig  iron  and  castings 134 

Impracticability  of  using  physical  tests  to  determine.  .144,  396 

Percentage  of,  in  different  brands  of  iron 145-147,  210 

High  temperatures  and  silicious  ores  required  to  make 

high    147,  161 


INDEX.  617 

Silicon— Continued.  PAGE. 

Percentage  required  to  change  the  grade  of  an  iron.  .150,  155 
The  influence  of,  to  retard  iron  absorbing  carbon.  .205,  208 
Its  utility  to  soften,  regulate  and  cheapen  mixtures.  .207-211 

The  first  to  advance  the  utility  of 207,  208 

Its  power  to  increase  the  fluidity  and  life  of  molten  metal  208 
Used  as  a  base  for  changing  the  grade  of  mixtures.  .208,  296 

Care  necessary  in  using  and  its  evil  effects 208,  209 

Percentage   used   in   light  castings 209-211,  281 

Point  at  which  silicon  hardens  iron 209,  281,  437 

The    highest    percentage    permissible    in    soft    castings 

. . 209,  281,  283 

Causing   brittle    castings 209,  222,  283 

Example  of  extremely  low  silicon  in  light  castings 209 

The  amount  that  can  be  absorbed  by  iron 210 

The  percentage  in  pig  most  desirable  to  use  for  regulat- 
ing   mixtures    210 

The  amount  of  scrap  that  four  per  cent  silicon  pig  may 

carry 211,  279 

Its  peculiar  appearance  in  fracture 211 

Amount  required  when  total  carbon  changes  in  order  to 

keep    a    uniform    hardness 246,  280,  282 

Loss  of  by  remelting 257,  303,  315,  341 

Low,  showing  a  greater  chill  on  edges  of  light  castings 

than   excessive  use  of 283 

Slags- 
Creation  of   52-53,  63,  66 

Amount  of  iron  in  furnace 53 

Defining  the  grade  of  iron  by  color  and  condition  of .  .     63 

Action  of  basic  and  acid  elements  in 63 

Chemical   relation  of  iron  to    65 

Percentage  of  silica  in 66 

Weight  produced  in  making  iron    66 

Methods  for  disposition  of 66 

Manufacture  of  mineral  wool,  from 67 

Slagging  Out- 
Percentage  of  refuse  carried  off  by 63 

Plans   used  by   furnaces 66-67 

Loss  of  iron  by,  in  cupolas 319-322 


6l8  INDEX. 

Specific  Gravity—  PAGE. 

Difference   between   gray   and  white   iron 219 

Remelting  iron  greatly  increasing  its 340 

Of  the  two  ends  of  vertical  poured  castings 378-381 

Expansion  of  iron  equalizing 381 

Test  of  solid  iron  floating  in  molten  metal 386 

Stretching  Iron- 
Percentage   in   tensile  tests 220 

Causing  castings  to  be  larger  than  their  patterns .  422,  428-429 
The   utility   of  in  permitting  the  manufacture  of  cast- 
ings     422,  430 

Description    of    appliances    used    for    testing 423 

Period  of  cooling  from  a  solidified  state  affecting.  .426-429 

Degrees  in  temperature  best  affecting 426,  429 

Demonstrations  of,  in  heavy  founding 428-429 

Expansion  of  large  cores  and  their  rods  causing 429 

Slow  and  uniform  cooling  assisting  stretching  and  sav- 
ing castings  from  cracking 430 

Standardized  Drillings- 
Origin    and    inception    of    plan    to    establish    a    central 

agency  to  distribute  standardized  drillings 182,  183 

Method   of  moulding  and  pouring   casting   for   making 

standardized   drillings    for   testing 184,186 

Method    of    turning    and    mixing    turnings    to    obtain 

standardized    drillings    186,  188 

Designation  of  samples  and  price 187-188 

The  labor  attending  the  introduction  of  standards.  .188,  190 
Names  of  some  firms  using  standardized  drillings.  .190,  191 
Testimonials,  in  praise  of  excellence  and  utility  of.  .192,  193 

Sulphur— 

Whether  exposure  of  coke  to  weather  reduces u 

Percentage  of,  which  coke  contains 21-22 

Scarcity  of  good  water  in  making  coke  increasing 22 

Evils  of  fuels  containing  high 22,  225 

An  approximate  quick  test  for  sulphur  in  fuel 22 

Percentage  of,  in  pyrites  and  methods  for  reducing  it 
in   ores    .  28 


INDEX.  619 

Sulphur— Continued.  PAGE. 

Irregularities  in  the  work  of  furnaces  regulating 53 

Affinity  of  iron  for  53,  225 

How  iron  obtains  53,  211,  341 

Found  greatest  in  the  top  face  of  some  pig  irons 134 

Spots  in  castings 138 

Percentage  in  different  brands  of  iron 145-147,  212 

Greatest  percentage  found  in  iron 147,  212,  225,  396 

Power  of  to  neutralize  the  effects  of  silicon 

150,  208,  212,  285,  303 

The  evils  of,  in  hardening  iron  and  causing  blow-holes 

211,  213,  225,  396 

The  power  of  to  increase  the  fusibility  of  iron 211 

Its  peculiar  effects  on  hardness  and  chill  of  iron 

2ii,  260,  271,  283 

Its  effects  in  making  molten  metal  sluggish  and  solidify 

rapidly  211 

Making  hot  short  iron 212,  213 

Excess  of,  weakening  iron 212 

Causing  excessive  shrinkage  and  contraction  or  holes 

and  cracks  in  castings  212 

Method  for  adding  sulphur  to  molten  iron 223,  388 

Ways  in  which  it  strengthens  iron 224 

Maximum  amount  of  sulphur  iron  may  absorb 225,  396 

Percentage  of  increase  by  remelting  iron 

257,  271,  302-305,  341 

Highest  percentage  permissible  in  light  castings 282 

The  length  of  time  iron  remains  in  cupola  affecting  an 

increase  of 341 

The  great  need  of  founders  fearing  the  evils  of 396 

Tables- 
Yield  of  coke  from  coal 13 

Tests  and  analyses  of  72-hour  coke 15 

Analyses    of   coke    from    six    different    localities 18 

Analyses  of  ash  in  Connellsville  coke 20 

Analyses  of   mill   cinder 32 

Analyses  of  three  different  brands  of  limestone 6l 

Analyses  of  slags  from  different  ores  and  iron 65 


620  INDEX. 

Tables— Continued.  PAGE- 

Volume  and  weight  of  nitrogen  and  oxygen 71 

Heat  production,  absorption  and  loss  in  a  furnace 72 

Segregation  of  sulphur  in  pig  iron 134 

Analyses  of  pigs  from  the  different  beds  of  a  change- 
able and  normal  working  furnace 135 

Silicon  analyses  of  the  different  beds  of  eight  casts 136 

Changes    in    sulphur    and    silicon    to    maintain    similar 

hardness    151 

Grading  pig  iron  from  No.  I  to  No.  10  with  an  increase 

of  .25  in  silicon  each  number 152 

Analyses  of  deceptive  pig  iron  samples  and  their  cast- 
ings       171 

Tests  taken  from  castings  made  of  deceptive  pig  iron. .   172 

Analyses  of  three  deceptive  pig  specimens 174 

Variations    of    the    analyses    of    two    test    samples    of 

drillings    ." 181 

A  method  of  keeping  records  of  chemical  and  physical 

tests    199 

Analyses  distinguishing  Foundry  and  Bessemer  iron....  215 
Test  and  analyses  of  sulphur  addition  to  molten  iron. .  223 
Tests  and  analyses  of  adding  phosphorus  to  molten  iron  231 
Comparative  fusing  tests  of  phosphorus  addition  to  iron  231 
Tests  and  analyses  of  variation  of  manganese  in  different 

irons    235,  236 

Percentage  of  iron  and  impurities  in  weak  and  strong 

castings    250 

Character  of  forty  specialties  made  of  cast  iron 252 

Methods  for  calculating  the  silicon  and  other  metalloids 

in  making  mixtures  of  iron 256 

Approximate  analyses  for  chilled  roll  mixtures 266 

Analyses  of  two  rolls  that  stood  well 267 

Analyses   of  car   wheels   that    stood   thermal   tests   and 

good    wear    268 

Analyses   of  car   wheels  which   did  and   did   not   stand 

thermal  tests    268-269 

Analyses    of    the    graphitic    and    combined    carbon    of 

wheels  which  stood  and  did  not  stand  thermal  tests..  270 
Mixtures    for    gun    carriages 274,  275 


INDEX.  621 

Tables— Continued.  PAGE. 

Mixture  for  semi-steel  275-276 

Mixture  and  tensile  strength  of  high  gracle  Salisbury 

carbonate  iron  278 

Approximate  analyses  of  coke  iron  mixtures 280 

Changes  in  the  relation  of  silicon  and  total  carbon  to 

maintain  like  hardness  282 

Analyses  of  dynamo  or  electrical  work  iron  mixture.  .  284 
Percentage  of  silicon  to  give  white  iron  in  varying 

thicknesses  of  castings 288 

Analyses  of  seven  typical  foundry  mixtures 299 

Transverse  and  tensile  tests  of  seven  typical  foundry 

mixtures  300 

Decrease  in  silicon  and  increase  in  sulphur  by  remelting 

iron  302 

Comparative  oxidation  tests  of  protected  and  unprotected 

surfaces  311 

Comparative  fusing  tests  of  gray  and  chilled  iron  by 

immersion  312 

Comparative  oxidation  tests  of  iron  charged  on  high 

and  low  beds  of  fuel 313 

Comparative  oxidation  of  stove  plate  and  heavy  iron.  .  314 
Analyses  of  silicon  and  manganese  each  from  low  and 

high  beds 315 

Analyses  of  iron  in  slag  from  stove  plate  and  heavy  iron  316 

Percentage  of  loss  of  different  irons  by  oxidation 318 

Comparative  fusing  tests  of  high  and  low  silicon  and 

low  sulphur  iron  with  analyses 328-329 

Analyses  and  specific  gravity  of  gray  and  chilled  irons.  .  334 

Comparative  fusing  tests  of  gray  and  chilled  irons 335 

Analyses  of  chilled  and  gray  same  iron  remelts 336 

Comparative  fusing  tests  of  cast  iron  with  open  hearth 

steel,  with  analyses  340-341 

Comparative  melting  points  of  cast  iron,  ferro-manga- 

nese,   ferro-silicon,   ferro-tungsten  and   ferro-chrome.  . 

352-353 

Tests  and  analyses  of  hot  and  dull  poured  chilled  irons. .  376 
Specific  gravity  of  the  upper  and  lower  end  of  vertical 

poured   castings,   with   analyses —378-379,381 


622  INDEX. 

Tables — Continued.                                                                       PAGE. 
Shrinkage  and  contraction  of  gray  and  chilled  iron....  411 
Influence  of  silicon  on  the  hardness  and  tenacity  of  iron.  437 
Analyses  of  car  wheels  that  did  and  did  not  stand  ther- 
mal  and   drop   tests    448 

Tests  of  gun  metal,  chill  roll  iron,  car  wheel  iron,  heavy 

and  light  machinery,  stove  plate,  and  sash  weight  iron, 

with    summary   of   their   transverse   and   tensile   tests, 

taken  with  V2" ,  i"  square  and  i^"  round  bars. ..  .460-467 

Summary  of  strength  averages  of  round  and  square  bars 

of   about    like   areas 469 

Rules  for  computing  the  relative  strength  of  test  bars, 

square  and  round    476 

Transverse  tests  of  bars  cast  flat  and  on  end,  showing 

the  evils  of  casting  flat,  with  analyses 493,  494 

Tests  and  analyses  of  remelted  furnace  casts  to  test  pig 

iron     497 

Tests  of  chill  roll  iron,  gun  metal,  car  wheel  iron,  heavy 
machinery,  stove  plate  and  bessemer  iron,  with 
analyses,  taken  with  il/&' ,  iffi  and  I  15-16"  round 

bars    536-537 

The  A.  F.  A.  transverse,  tensile  and  compression,  tests  of 
bessemer,  dynamo  iron,  light  machinery,  sand  and 
chilled  roll,  sash  weight,  car  wheel,  stove  plate,  heavy 
machinery,  cylinder  iron,  novelty  iron,  and  gun  iron, 

with    analyses    558-570 

Net  weight  of  sand  pig  iron  per  ton  of  2,268  pounds.  .  589 
Net  weight  of  chilled  pig  iron  per  ton  of  2,240  pounds. .  590 

Chemical  symbols  and  atomic  weights    591 

Value  in  degrees  centigrade  for  each  100  degrees  Fahr.  .   591 
Heat  of  combustion,  and  scale  of  temper  by  color  of  iron  592 
Melting  points  of  metal,  relative  conductivity  of  metals 
for  heat  and  electricity,  specific  gravity  and  weight  per 

cubic   inch   of   metals 593 

Ultimate  resistance  to  tension  in  pounds  per  square  inch 
of  different  metals,  strength  of  different  woods  and 
table  of  decimals  equivalents  of  the  fractional  parts 
of  an  inch  594 


INDEX.  623 

Test  Bars,  Patterns,  Moulding  and  Casting—  PAGE. 

Design  of  and  method  for  using  fluidity  strips  to  record 
the  fluidity  of  metal  374,  502,  515-517,  519 

Design  of  pattern,  flask  and  chills  for  moulding  single 
round  bars  flat,  but  cast  on  end,  with  fluidity  strips 
attached  507-510 

Instructions  for  moulding  and  casting 508-510,  523-527 

Decimal  equivalents  for  iW,  I5A"  and  I  15-16"  diame- 
ter   510,  520 

Design  of  patterns,  flasks  and  chill  for  moulding  two 
rou.nd  test  bars  flat,  but  cast  on  end,  with  fluidity 
strips  and  chill  attached  512,  521,  522 

Designs  for  half  circle  chills  and  contraction  tips  for  use 
in  casting  round  test  bars  on  end 517 

Plan  for  obtaining  contraction  and  making  whirl  gates. 5 18-5 19 

Plans  of  patterns  and  moulding  bars  to  be  turned,  either 
for  transverse  or  tensile  testing  520 

Plans  for  moulding  and  casting  plain  bars  on  end 

521-522,  527,  578-580 

General  instructions  on  moulding,  swabbing  and  pour- 
ing   • 523-527,  579-580 

Design  of  patterns,  chill,  fluidity  strips  and  flasks  used 
for  the  A.  F.  A.  series  of  tests 542-544,  546,  548,  549 

The  floor  space  and  amount  of  labor  required  to  mould 
one  set  of  A.  F.  A.  test  bars 542,  550,  552 

Description  of  plan  of  moulding  the  A.  F.  A.  test 
bars  542,  545,  547,  548-558 

Test  Bars- 
Difference  that  variations  in  dampness  of  sand  and  pour- 
ing temperatures  make  in  the  strength  and  contraction 

of   small    T/2-inch   bars 453,  457,  484,  511,  525 

Unreliability  of  as  small  as  ^-inch  square  or  round.... 

454-456,  467-468,  484,  511 

The  size  of  test  bars  most  suitable  for  testing  different 

grades   of   iron    468-469,  477,  533,  535,  573 

Comments  upon  the  difference  in  the  uniformity  of  grain 

exhibited  in  round  and  square  bars 469,  486,  576 

Formulas  for  computing  the  difference  in  area  of  test 


624  INDEX. 

Test  Bars— Continued.  PAGK. 

bars  made  off  the  same  pattern  and  tested  the  same 
distance  between  supports  474,  476 

Necessity  of  records  being  taken,  of  the  least  difference 
in  the  area  of  bars  made  off  the  same  pattern 475 

Impracticability  of  formulas  in  vogue  (to  1902)  for  com- 
puting the  strength  per  square  inch  of  cast  iron  in 
different  cross  sections  and  lengths  477,  530 

Utility  and  necessity  of  using  a  micrometer  to  measure 
the  area  of  478-480 

The  impracticability  of  casting  two  test  bars  of  exactly 
the  same  area  at  the  breaking  point 479 

Manner  in  which  test  bars  should  be  placed  for  trans- 
.  verse  testing  481-482 

Comparison  of  lines  of  crystallization  in  round  and 
square  483-484 

Uneven  cooling  causing  internal  strains  in   485 

Examples  of  the  uniformity  of  grains  in  round  and  non- 
uniformity  in  square 486-487 

Indorsement  of  the  A.  F.  A.  of  round  bars  and  recom- 
mendation of  i^-inch  diameter  as  the  smallest  to  be 
used  .487,  573,  576,  577 

Deductions  from  tests  showing  the  evils  of  casting  bars 
flat  and  the  difference  in  the  results  of  such  methods.  .  489 

The  importance  of  having  uniform  temperature  of  metal 
in  pouring  526,  527,  540,  547,  580 

The  utility  of    ..  .. 528-531 

The  different  area  and  lengths  of  bars  in  use 530 

The  practicability  of  using  bars  i1/^"  diameter  and 
larger 533,  573 

The  necessity  of  using  one  size  of  bar  in  making  com- 
parative tests  of  one  or  more  grades  of  iron 533,  575 

The  grade  of  iron  that  either  one  of  three  bars  recom- 
mended by  A.  F.  A.  and  the  author  are  best  suited 
for  533,  577-579 

The  first  set  of  test  bars  made  for  the  A.  F.  A 541 

The  character,  size  and  number  of  test  bars  made  for  the 
A.  F  A 551,553 


INDEX.  625 

Test  Bars— Continued.  PAGE. 

Making  records  of  depressions  at  point  of  bearing  in  not- 
ing deflection  of   555,  576 

The   adoption   of  the   round   bar   for  testing,   by  the   A.   F. 
A 576 

Design  and  size  of  the  A.   F.  A.  bars,  used  for  trans- 
verse  and  tensile   tests    582,  583 

Testing  Iron,  General — 

The  character  of  strains  that  cast  iron  is  generally  sub- 
jected  to    220,  439 

Advisability    of    taking    drill    tests    and    testing    chilled 

castings     259,  432 

Effect  of  different  temperatures  in  varying  the  depth  of 

chilled   iron    262,   372-374,  433 

Melting  of  brands,  grades  or  mixtures  in  small  cupolas 

for    267,  325,  362,  495-502 

Methods  that  are  misleading  in 277,  492,  576 

The  best  test  for  softness  in  light  castings 283 

Utility  of  transverse,  crushing  and  impact  tests. 439-445,  448 

Methods  for  testing  car  wheels 440 

Erratic    and    impractical    records    compiled    previous    to 

1895     449,  539 

Evils  of  casting  bars  flat  for 449,  488 

Analyses  of  the  corner  and  middle  body  of  square  test 

bars    45I-4S3 

Comparative   transverse,    deflection   and   tensile   tests   of 

il/i"  round  bars  in  gun  metal,  chill  roll,  car  wheel  and 

four  other  specialties    (analyses  shown  page  299)  ....  466 
Comparative  tests  showing  that  for  the  same  area  round 

bars  record  a  greater  strength  than  square  ones 469 

The  first  tests  collected  of  different  grades  of  iron 470 

Opportunities  offered  for  deception  or  jugglery  in  testing 

bars  cast  flat   492 

The  cost  of  a  set  of  appliances  for  casting  and  testing 

round   bars 499 


626  INDEX. 

Testing;  Iron,  General —  PACK. 

Comparative  transverse  and  deflection  tests,  with  il/&", 
i$/i"  and  I  15-16"  bars,  of  chill  roll,  gun  carriage,  car 

wheel,  heavy  machinery,  stove  plate  and  bessemer 
iron,  with  analyses 535-537 

Conception  of  the  plan  to  pour  several  tons  of  bars  out 
of  the  same  ladle  and  at  the  same  temperature,  as 
used  by  the  A.  F.  A.  in  making  1601  tests 540 

To  whom  credit  is  due  for  making  the  A.  F.  A. 
tests  540,  542,  555 

The  difference  in  strength  which  the  A.  F.  A.  green  sand 
and  dry  sand  bars  show 557 

Comparative  transverse,  deflection,  tensile  and  compres- 
sion tests  from  finished  and  rough  bars,  cast  in  green 
sand  in  12  different  grades  or  specialties  of  iron  mix- 
tures as  cast  for  A.  F.  A 558-570 

Compilation  of  the  A.  F.  A.  tests  showing  the  transverse, 
tensile  tests  per  square  inch  radicallv  receding  in  oppo- 
site directions  above  an  area  of  il/2"  diameter.  ..  .571-572 

Comments  on  the  difference  in  strength  of  round  and 
finished  bars  obtained  by  A.  F.  A 572-573 

Report  of  the  A.  F.  A.  committee  recommending  specifi- 
cations for  tests  of  cast  iron 574-584 

The  inadvisability  of  taking  coupons  or  tests  from  a 
casting  as  a  guide  to  the  casting's  strength 576 

Tensile  Tests- 
Strength  of  some  especially  strong  iron  mixtures 

275,  276,  278,  300,  344 

The    practicability    of    tensile    tests 449 

The  relation  tensile  tests  bear  to  transverse  when  kept 

under   i^-inch   diameter    450,  571 

Difficulties    encountered    in    testing 450 

Designs  of  bars  for  making  turned  bars  for 458,  583 

Compilation  of  strength  per  square  inch  of  rough  and 

finished  bars  as  obtained  by  A.  F.  A 570 

Transverse  Tests — 

The  best  for  general  use  in  testing  cast  iron.  . .  .220,  277,  439 


INDEX. 

Testing  Machines—  PAGE. 

The  necessity  of  and  care  in  using 481 

Advisability  of  a  uniform  speed  in  operating 481,  577 

Plan   for   delicately   operating  hand 482 

Thermal  Tests— 

The  value  of  manganese  to  assist  iron  to  withstand....  271 
Methods   of  applying  to  car  wheels 443,  444 

Titanium — 

Nature  of  its  effects  in  iron 31,  218 


PRACTICAL  WORKS  BY  A  PRACTICAL  MAN. 

Known  world-wide  for  their  value. 

American  Foundry  Practice 

A  IV  D 

Moulder's  Text  Book. 

By  Thos.  D.   West. 


These  standard  works  have  as  large  a  sale  today  as  when  first 
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In  a  review  of  the  tenth  edition  of  American  Foundry 
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MANY  BEGINNERS  AND  SKILLED  HOULDERS  AND 
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SHOULD  HAKE  A  STUDY  OF  THEM. 

American  Foundry  Practice  now  contains  408  pages  and 
Moulder's  Text  Book  518  pages,  both  nearly  the  size  of  this 
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Published  by  John  Wiley  &  Son,  New  York,  and  sold  by  almost 
all  prominent  book  dealers.  Price,  $2.50  per  copy,  postpaid. 


YB  24361 


